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Vorshlag S550 & S650 Mustang Development + 2018 GT, 2024 Darkhorse & #Trigger

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  • #16
    Re: Vorshlag 2018 Mustang GT + S550 Development Thread

    Project Update for July 26th, 2018: It has been a hectic few months since my last post, and it took me nearly 3 weeks to finish this post after I started writing it. We have been dealing with moving our business into a new shop and finishing construction on this new building, which I talk about at the end. It also got VERY hot here in Texas in June and July. Due to time and heat we haven't run the car since our last two track events in May. But we have a lot of testing and competition events to cover since my last post.

    I failed to cover many of these in the last update, even though some of them had happened already. We had a Track Night in America road course test at NOLA (April 12), competed in an Optima 2 day event at NOLA (April 14-15), did another private track test at MSR-C (April 22) to test some brake system changes, competed in a NASA Time Trial at COTA (May 5-6), and an SCCA Club Trials event at MSR-C (May 12).

    I will try to cover these events as well as some upgrades and changes we tested on our 2018 GT, then list some of the many parts piling up waiting to be to installed - when we have a few hours to spare to work on a shop ca.


    I don't hide it: for most events we take this street legal Mustang to, I would rather tow the car there in our enclosed trailer. There are several reasons for this: to avoid tire issues on the road (like the blowout we had last time?), to reduce the heat cycles on the tires (even 200 treadwear RE-71Rs are susceptible to aging out), and to be able to bring ALL of our gear to the track in comfort and security (tools, spares, bikes, food, covered shelter, etc). After an exhausting weekend at the track it sure is nice to ride home in a big cushy seat inside the F350 - with no worries.

    Strapping down a car safely to a trailer deck takes time and the right gear. To speed up this process we always try to make or buy some tie-down hooks for every shop car. We make tie-down hooks (below) for the rear of the S197. But the kit (shown above right) that Ford makes for the S550 looked good, so I bought a set.

    The Vorshlag trailer tie-down hooks for the S197 Mustang rear are very handy for trailer towing

    I mentioned in my last post how that the Ford M-1700-M kit we tested makes hooking the tie-down straps to the S550 chassis a whole lot easier. For less than $90 it was worth a try. We have pictures to show them - but we didn't install two of the hooks where Ford intended.

    So the rear hooks were bolted to the two threaded holes on each side of the chassis, as Ford intended. These are just inside the "lower pinch weld" in front of the rear tires. With two 3" wide straps from MAC's we cross the tie downs and hook into D-rings on the floor behind the car. IT is easy to toss the straps up in front of the rear wheels, grab into these loops bolted to the floor, and strap the car down from behind.

    They intended that you do the same on the front, but with so much front overhang and a low front ride height, it is much harder to toss the straps behind the front wheels from the front.

    When we had the car on the lift I asked the guys to drill holes and bolt them to the beefy front subframe, as shown above. These are much closer to the front of the car, but still bolted to something very substantial. Makes it easy to reach under the nose and hook to these locations - at least until we add a splitter. Then we might move them back to the spots behind the front wheel... YRMV.


    There is a reason I am sharing this section because the road course lap times on the NOLA 2.75 mile road course our 2018 GT, at both the TNiA test and Optima event (see below), were downright dreadful. I just wanted to make sure that readers understood that A) this was not my first time at this track and B) that I'm not some total squid who drives like Mr Magoo on course! Please indulge me for a minute while I list my bona fides at NOLA...

    I made this track map from the NOLA Motorsports Park's 2.75 mi CW road course back in 2013, when I ran my first competition event event there in our 2011 Mustang GT with NASA in TT3. The track layout hasn't changed since, except for maybe getting a bit faster with some added pavement at the exit of Turn 16 (it used to be grass).

    Before 2013 I got to make a some laps here in 2012 at a BFG tire test driving a Mustang Challenge/Miller Cup FR500S race car (above). I also ran here with NASA again in 2017 in our TT4 prepped BMW 330 (below). So I had a decent number of laps at this track, had two wins in TT4, two wins in TT3, and set a TT3 class track record that was only recently beaten.

    To compare times between our S550 and our S197, let me explain a bit about that 2011 GT's "TT3" prep level in 2013. When we came here then we had just moved this Mustang into the brand new TT3 class. It was on Motorsport shocks/springs, but had pretty crude aero (APR rear + plastic LS faux-splitter), when compared to later seasons. We were on the smaller 18x11/18x12" wheels under stock fenders, only running 315/30/18 Hoosiers (we later ran 335/345 tires with flares). We brought 3 sets of tires to that 3 day race weekend: 295mm street tires we used in rain testing on the Friday before, a used set of A6 tires (which Amy and I both drove on Saturday), and a sticker set of new A6 tires (which I set the track record with on Sunday morning, in my one lap that day).

    TT3 track record setting lap in May 2013

    That 1:50.535 lap stayed the TT3 class record from 2013 until May of 2018 - a five full years. So I guess my 2013 drive here was one of my better ones, but the car got considerably faster in 2014 and 2015, so it wasn't what a max-prepped TT3 car should do there today. But not far off. We're running this S550 in TT3 class now as well (but on street tires) and for comparison: at Eagles Canyon's 2.5 mile track it is currently 5 seconds back from our S197 best lap there (still the TT3 record, set in 2013), and 4 seconds back from our best TT3 lap at MSR (we held that record in our S197 from March 2014 until March 2018, 4 years). So if you extrapolate the differences from these 2 tracks, I was hoping to run a 1:53 to 1:55 lap at NOLA (I did not). Also, we've set our best laps in the S550 on the wimpy 14" OEM brakes, which are far worse than what the 15" 6 piston brakes should do on this car (which should be worth another 1-2 seconds, even on street tires).

    Last October I ran our BMW 330 in TT4 class, on a little 245mm R7 tire and 40 hp down on the class limit (really a TTD car with a wing added), but with decent suspension, brakes, and aero. My best lap of 1:56.029 wasn't a class record, but it was enough to win the class both days - barely. I drove the piss outta that BMW hunting for tenths, eventually clipping the pit wall on the exit of T16 and popping the side mirror off in the process. This BMW needed more POWER to drop into TT4 lap record range (1:54s), but the aero and brakes worked well enough to sneak in the two class wins.

    In 2013 I went over to a Delta Region SCCA autocross during the NASA TT event after their final runs, made two "fun runs" just site reading the course (with Mark Council navigating from the passenger seat), and was quicker than FTD (on my second, cone-free run). So I had good luck at this autocross pad, too. All of those "nothing but wins" history at NOLA gave me a false sense of hope of maybe doing well at the Optima road course and autocross competition segments. But we had unknowingly hobbled the S550's brake hydraulics when we added the 15" PP front calipers - we made the already poor 14" brakes even WORSE. I will explain...


    Last time I showed how we moved from the non-track worthy 14" inverted hat front rotors and 4 piston calipers to the "normal" vented 15" rotors and 6 piston calipers sourced from Ford Racing / optional S550 Performance Pack. At the same time also upgraded to more aggressive G-LOC pads front and rear, added our prototype front brake cooling package, and installed our front and rear tow hooks. I drove around the block and the brakes "felt fine" in a few 60 mph stops - this was right before we put the car in the trailer to tow 9 hours to New Orleans. I said was not going to get caught without adequate brakes again. The best laid plans...


    We thought we were being sneaky and had signed up for the Thursday evening Track Night in America event with SCCA - to get some road course testing in on the same 2.75 mile course that Optima would run. Well many of our Optima competitors figured this out as well, so it was a crowded track event. We showed up at 2 pm, unhooked the trailer, unloaded the car and got ready for a 3 pm driver's meeting and I was on track by 3:30.

    All I could muster were some 1:58.1 laps in the first session - uh oh. But well... there was a LOT of traffic, all gridded out of order. The brakes just didn't feel right, and the car would not stop well at all. By the 2nd session I took a rider (Optima racer who didn't know the track) and ran some 2:02 laps, and that's when I knew I was in deep trouble. There's no way this car should be nearly 8 seconds off the pace of our TT3 car! Tires were sliding, hot pressures were only 30 psi, so I bumped them up 2-3 psi.

    I was chasing what I thought were setup issues, but it really didn't dawn on me how bad the brakes were until late on Sunday. Why? Well I was running down the faster TNiA guys Thursday and even ahead the GT class on Sunday morning at Optima. I was ignoring what I felt and focusing solely on lap time placement in early sessions that didn't matter.


    Friday we slept in late, then went out to the track at about 2 pm to tech for Optima, installing all of the sponsor decals, and I did their fire exit drill test (actually pretty thorough). Talked to a lot of friends and competitors, Amy and I helped a lot of folks put their decals on, and we somehow stayed out there until 6:30 that night getting ready for the Saturday-Sunday Optima event. Productive day, and we had excellent seafood that night with friends.



    Now I haven't done an Optima event since 2015 so I was a bit out of practice. There are at least 5 classes now - I'm going to ignore most of them and concentrate on the GT class, which is for 3200+ pound 4 seat cars, mostly made up of Mustangs, Camaros and Challengers. If I talked about all of the classes and friends we had here this write-up would never end.

    Saturday we were at the track early, but we were all rushed. They held the driver's meeting early (still took a long time), due to a 100% chance of major rain later that day.

    Left: 400#/in rates with Whiteline dampers, 19x11/305 RE-71R. Right: Matt's '15 PP1 on R springs/shocks, camber, same wheel/tire

    Everything on the schedule that day got compressed down, all to try to run the autocross before the skies opened up and dumped 6" of rain on the track facility in about 2 hours. We got to the autocross course and the GT class entrants (33!) got either 2 or 3 dry runs in before it started to get damp. Since we had no idea when it would start I took a very aggressive first run - but since I didn't walk the course (due to the compressed schedule) I figured that run would be junk. Turns out it was not only my best run, but the best run for all of GT class that day. I even got lost in the middle section, and of course I forgot to turn on the vidcam, because I was so rushed.

    I took my 3rd run in the rain, just for fun... and the Optima guys took this driftoro pic and posted it with my own #Jankystick superimposed! Beaten with my own janky stick of doom!

    continued below
    Terry Fair -
    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


    • #17
      Re: Vorshlag 2018 Mustang GT + S550 Development Thread

      continued from above

      Turns out my fastest autocross run was only 10th quickest overall out of 84 total entrants. The only video worth showing (below) was my wet run # 3, where I was just hooning. In the end I only won the GT class autocross portion by .003 sec, but I'll take it. I'm not that good at autocrossing, just sometimes very lucky.

      Next, we got in line for the Design and Engineering judging, where the REAL rain came in. Man it just poured, for hours. People were seeking shelter and the D&E judges took their time.

      Everyone got soaked and we didn't get outta there until 5 pm that night. That's when I found out that my first autocross run was good enough for the win! And this was my first autocross run ever in this car. Dumb luck - but I'll take it. I still felt like my performance in the Speed Stop and Time Trial portions would kill me, due to the bad feeling about the brakes from Thursday (not to mention the horrendous D&E score that we go, which was even worse).


      Sunday turned out to be a PERFECT weather day, but my competition results were taking a nose dive. Sunday was the day that I would fall way back in GT class standings. Sure, the D&E judging was a bloodbath for us, in a nearly stock Mustang, but early on I still felt we could beat the GT class on track and maybe score top 5 in Speed Stop. WRONG.


      For this Time Trial portion each competitor had four 15-20 minute sessions on track Sunday. It was a little damp in the first session yet right off the bat I was the quickest car in "Intermediate" group in the first session and had the fastest time in GT class. Optima splits the track drivers into 3 groups: Beginner, Intermediate, and Advanced - with different passing rules and safety requirements for each. We haven't had time to add racing seats / harnesses / roll bar to this car, so I couldn't run in the "Advanced" group. As luck would have it, the two Intermediate groups had fewer cars, and once I got gridded closer to the front, the on track traffic I saw in session 1 went away. The "Group" you run does not affect your "class" standings, just the passing rules and who the other cars you are running with.

      But as the day progressed over four track sessions my fastest lap time only dropped by a total of 1.1 seconds. All of the GT class competitors that ultimately went faster than me improved their morning best lap times by 3-6 seconds. As the sessions clicked off I fell to 2nd in class, then 3rd, then all the way down to 7th in class. I got beat like a drum!

      quick look at "Hot Laps" road course results, by session

      On a positive note, I got slightly quicker each session, but I was only finding tenths. Obviously my times got swamped by 3 full seconds, with 7th out of the 33 cars in GT and 20th overall. Just a dreadful result for how I've done here in competitions in the past. To compare, my best lap was a 1:56.867 which was 6.3 seconds slower than my 2013-seaon TT3 S917 and still a second slower than my BMW 330 - which had over 200 less hp and was on 245mm tires. At the MSR-Cresson 1.7 mile course with the crappy 14" brakes my S550 lap is 3 seconds faster than my 330 - another indicator of how far off the pace this Mustang is with botched brake hydraulics.

      Watching the video below showing my 2 laps in session 4 of the "Hot Lap Challenge", you can hear me complaining loudly about the brakes as I was struggling to get the car stopped. The g-traces look good laterally (1.25 to 1.3g) but in braking the best you see is a brief spikes of 1.05g then it quickly trails off to .8g stopping. The tires were doing their job but the brakes just couldn't load them up. I was braking 200 feet sooner into T1, 100 feet sooner into T13, etc.

      Video of my 4th session and quickest lap on track - which was SLOW!

      The brakes never felt bad, it was just that the car was just not stopping. The harder I pressed the pedal, however, it stopped ever so slightly better for a brief moment - to the point that I was using my entire upper and lower body strength trying to pull up on the steering wheel and press down on the brake pedal SUPER HARD to eek out a tiny bit more stopping power. You cannot do that level of effort and concentrate well on driving, so in the g-traces you can see that brief spike in braking g's, then I would slowly ease into turning then onto the throttle on exit. Too slowly - it looks like some coasting in there, plus the fact that I'm not on the gas when I am still having to brake hundreds of feet early.

      The result was that the 14" brake master cylinder was putting too much hydraulic force bias into the rear brakes, and the ABS was pushing back against rear lockup. This made the rear tires also dip into oversteer at corner entry, which I comment about several times in the video. With so much energy going into the rear brakes it is no wonder the tires were getting overworked out back.

      Somebody driving 7/10ths of a car's potential on track might not even notice it, but they'd be 4-5 seconds off the ultimate pace of the car if it had good brakes, just like I was. To do all of this upgrade work - bigger brakes, new pads, brake cooling, drive 9 hours to this event - only to make the car slower, kinda sucked. And of course it had to happen at the televised Optima series event, and not at a local test day (we had no time). I doubt the interviews that were filmed (after my autocross win) will ever be seen on the TV series that follows this series, due to my poor overall performance. But that's how this works - you don't get on TV when you finish 10th, and you don't test new setups at big events. I know better!


      As you can imagine, the brake intensive "Speed Stop" competition times were even worse. If you are look at the times for my left and right side course it doesn't look that bad, but it really was. My 11.2 sec (left) and 13.7 sec (right) runs were each about a half second per side off of the GT class SS winner Chad Langley's 2018 Chevrolet ZL1 times of 10.8 / 13.1 seconds. But that's an eternity, and I was buried down in 9th place in class and 26th overall in Speed Stop. I'm not even showing any video of that hot mess. I had great launches, and the slalom speeds / lateral gs were great, just no stopping power.


      My overall GT class standing (10th place) was worse than any of my individual competition finishes due to the horrific D&E score (car show stuff) the car received.
      Because of how they score the overall points, even if I had taken first the road course and speed stop and autocross, I wouldn't have won GT class. It all comes down to D&E judging - but hey, that's part of how this series works, and I get it. It still didn't make it sting any less to barely finish "top 3rd" after starting out by winning the autocross portion.

      Overall the Optima/USCA folks did a stellar job running this event, and we STILL had fun for the 4 days we spent in New Orleans. Considering the flash flood they had to work around, it was quite amazing.

      Getting to see my nephew, niece, and grand nephew (?!) while we were in town made it that much better. I also got to see a LOT of friends who run Optima events and/or have similar shops to Vorshlag who I hadn't seen in a long time. I'll be back, Optima. And I will have brakes!


      One person online had warned me that the master wasn't right for the 15" PP brakes, while dozens said otherwise. I listened to the wrong people this time. The day I got back from Optima, I was hopping mad - at myself - and immediately asked Jon to order a 2018 GT PP1/PP2 master cylinder and booster.

      In my last thread update I showed how we moved from the non-track worthy 14" inverted hat front rotors and 4 piston calipers to the "normal" vented 15" rotors and 6 piston calipers from the optional S550 Performance Pack. I drove around the block right before we put the car in the trailer to head to New Orleans. I and made a few aggressive stops on the street and it "felt" fine. That's the problem - the pedal feel in regular street driving is close enough, and I feel that's what people who are doing this upgrade are feeling. But it is moving a LOT of brake bias to the rear when using the 14" master cylinder. The hydraulic math proves that (9% front piston surface area change).

      Of course, as you read above about our NOLA Optima weekend, this 15" brake with 14" master cylinder setup didn't work. AT ALL. I could press the brake pedal hard enough that it felt like I was going to break something - yet the car would just barely slow down. The g load traces under braking tell it all.

      I am not trying to start controversy here, but the on track g-trace data, lap times relative to my other drives at this track, and hydraulic math all prove this out. There is a reason why the master cylinder is different on the base vs PP1/PP2 cars. You can see me measuring it in the accompanying video. Its a big difference. I simply could not make this car stop on the 6 piston calipers pushing with the hydraulic master and booster from the 4 piston brakes.

      At the same track in our S197 with smaller 14" brakes I could brake 200 feet later into Turn 1 and 100 feet later into T3, T5 and T13. In the 4th session I did some lead-follows with Matt's 2015 GT PP1 car and he could outbrake my car by 100+ feet on every corner with the exact same wheel and tire, the same brake parts (15" PP bits), and he was even using bargain priced Powerstop brake pads. I was on a better pad on the "same" brakes, the exact same wheels and tires, where only difference was the master cylinder hydraulics.

      And when you look at the caliper piston surface area differences, the 15" 6 piston brakes shouldn't have worked without the proper master cylinder from the PP. Some people swear by that 14" hydraulics with 15" brakes setup. Others swear that the backwards 14" brakes work fine on track, too. My theory to explain those statements is this: maybe those people just aren't that fast. Inadequate brakes for one person might be fine if they were pushing the car 50% or 75% as hard. So yea, people driving slower might not notice some of the issues I remark about, but when I push a car on track in "qualifying" type laps, limitations start to become very apparent. I have been doing road course events for 30 years, driven tens of thousands of laps in hundreds of different cars. I am not saying I am better or worse than those that argue against me - just that I have a lot of seat time, data, math, testing and results to back up this claim.

      S550 Brake Hydraulics Explained

      The video above shows the bore measurements of the base 14" brake vs 15" brake PP2 master cylinders for the 2018 model Mustang GT, the two boosters, how we installed them, and even the removal of the "sound tube" and plastic engine cover. The 1.5mm difference in master cylinder bores matches the same relative difference in piston surface area from the 14" 4 piston to 15" 6 piston calipers - which might just be why Ford makes two different master cylinders for these two brake packages, right? Why, you ask, does Ford Racing sell the 15" 6 piston brake kit (M-2300-T 4 wheel or M-2300-V front only) kits without the related Performance Pack master cylinder and booster? That I cannot answer - but trust me, you need the matching master and booster. I am not trying to sell you anything here, just trying to save you grief.

      Once we tracked down the right part numbers (they are in the images and videos above) we installed the correct PP1/PP2 master cylinder and booster (thanks to tips from the engineers at Powerbrake, who verified the math) on brake mod round 4, then went back to MSR-Cresson for some brake testing (track test #6, below).

      continued below
      Terry Fair -
      2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
      EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


      • #18
        Re: Vorshlag 2018 Mustang GT + S550 Development Thread

        continued from above

        TRACK TEST #6: MSR-C, APRIL 22nd, 2018

        This was an unusual and short test day for us. This was a Sunday "member day" at MSR, so I arranged to go with our tester Jerry, who has a membership. He had a bit of a delay that morning so we did not get out there until about 1:45 pm.

        The track had double-booked a Camaro club event to run a few sessions on track that afternoon, so it was crowded, and we didn't get on track until 3:30 - the hottest part of the day. It was also the last member session of the day, so the members that were still there all came out to run at once.

        I took what I have learned from running this car over the previous 2 months and put it into practice - I filled the tank full of 93 octane, to prevent fuel slosh in the high speed corners. I tried to get the hot tire pressures to 35 psi (by starting 30 psi front, 31 psi rear cold). We towed the car out to the track, to prevent any flats or mishaps. And I made it to grid first, to try to get some traffic-free laps early.

        Well even going out first, I caught the field still coming of the pits in the middle of my first hot lap. Then I fought for 10 hard laps looking for a traffic-free lap, but the tires were too hot after lap 3. Brakes got the slightest hint of fading after 7 laps but I could still push the brakes HARD. Track temp was measured 100°F, ambient was around 68°F, but I was still fighting tire heat after just 3 laps. 10 laps into this 20 minute stint I dove into the pits, Amy checked brake temps and tire pressures, and the right side tires had crept up to 40 psi! She bled all four down to 35 psi and I went back out on track in the same session for 7 more hot laps. The tires were still blisteringly hot. #500psi

        In the end I managed to test the brakes well in this solid 30 minute session, over in two stints, and it told me all I needed to know. The pedal effort required to stop at 1.05-1.10 g was normal. The hydraulic issues were gone, and I only saw minimal fade when pushing the brakes hard over 17 laps.

        Some in-car video and test evaluation

        In the video above I show one of several 1:23.1 laps, but never got clear track when the tires were "in the operating range", so I thought this was why I could not reach the previous best lap in this car here (1:21.9, NASA weekend in cooler weather). Going a second slower than my previous best lap, with bigger brakes, and I am calling that successful? Yes. More on this in Test #8, where I matched these tires again.


        These Bridgestone RE-71R tires are made to get up to operating temperature FAST, and they perform best in their 1st or 2nd lap on track. The wear rate is somewhat in line with an "R" compound race tire, too (we have 8 events on this first set and they are wearing thin). We saw the same thing in the Focus RS testing at the same track on the same tires. Do these characteristics sound familiar?

        My suggestion is to treat RE-71R tires just like a Hoosier A7. Minimize heat cycles and run them in very short stints. Get out on track, minimal scrubbing on out lap, get a fast lap in quickly (within 1-3 laps), then come in and let them cool down. The RE-71R really is not a casual, daily driver, lap-it-all-day kind of tire. Its a "200 treadwear" ringer tire. Doing 17 laps in one session on them was enlightening.

        If you do want a "lap it all day" type of tire that is similar but lasts longer... the Hankook R-S4 is your answer. They have a lot of the same sizes as the Bridgestone, are a little cheaper, are a bit slower, but last a bit longer - and can deal with heat better over more laps. #TheMoreYouKnow


        Talked to a GT350R owner who was running earlier at this same member day and he was super happy with his Vorshlag camber plates, supplied and installed by one of our dealers Doghouse Performance, located here at MSR. They setup up the car with max camber of almost -4.0° and it has helped him run his best ever lap time of a 1:23, and with a pro driver it has run a best of a 1:21 lap here.

        A few weeks later I saw this image below on the Doghouse Facebook page, from a similar/maybe the same car... "We saw this failure on a Shelby GT350R with 2,600 miles on it yesterday. That is a connecting rod cap and bolt jammed through the composite (plastic) oil pan. Zero missed shifts. Car lost oil pressure then died instantly with zero warning."

        These Voodoo 5.2L engines have a good bit more vibration than the Coyote 5.0L due to the weird 180° fire crank. We are hearing about more and more oil pressure related failures, for sure. Even pro racer and test driver Randy Pobst has come out publicly about the issues with the Voodoo V8. If you own one just make sure that oil filter stays tight and doesn't fall off, people! I would check that literally before each session.

        NASA AT COTA, MAY 5-6th, 2018

        After a two week break, we were off to COTA to race with NASA on the big boy F1 track! Super excited, and while I have run here 3 times previously, I have only run COTA once in competition. After track test #6 I was at least semi-confident in the 15" brakes now, but could they stop well from 145+ mph, lap after lap? Also, could a 3950 pound street car on Bridgestones hang with race cars with max aero and Hoosier A7s? Well... don't hold your breath.


        We got there on Friday mid-day, in the pouring rain - nobody got any decent testing that day, due to lightning that shut the track down for most of the day. Glad we didn't spend the $500 for that Test-n-tune day.

        We unhooked the trailer, unloaded the car into our garage space, then busted outta there. Met up for a nice dinner at Javier's Tex Mex with a lot of racer friends, near the airport where all of the hotels are.



        Early 6:40 am meeting for Instructors and then a TT meeting at 7 am. TT was out on track first and it was still wet - and I was SLOW running some 2:44 laps, trying to remember the line in a car I had never driven here. My BMW 330 lap times from 2017 were in the 2:42 range, which has now held up as the TTD track record through this weekend - somehow.

        The track layout was different from 2017 with the removal of the big yellow curbs (sausage curbs) at the exits of Turns T11, T12, T19, and T20. The track limits for TT were also reset out past the second white line (which was past two sets of gator teeth curbing and big green painted patches). This change in limits could be worth 2+ seconds over last year, when we had those curbs to keep us in-bounds and away from 20+ feet of paved runoff.

        I gridded for the first session in 14th, and then worked my way up the grid from there. After driving all four TT sessions and even an HPDE4 session, where I took my first student around for some coaching laps, I managed a best of 2:34.693 lap in TT competition Saturday. My first HPDE student Chris had a 2016 S550 Mustang GT automatic - and he had also just done the 15" PP brake upgrade without the PP master/booster. We noted significantly longer stopping distances than my car, but he was also on Hawk pads running about 15 sec/lap slower. Again - not everyone is going to feel the need for the correct master cylinder, but it does matter. His automatic trans equipped car never went into limp mode, and he was relatively quick for DE1. He was signed off for Solo in DE2 later that day I ended up working with 3 more students over the weekend.

        The brakes on my 2018 felt "fine" all day. Sure, I could fade them after 2 hot laps in a row with some 145 mph stops going into T12, but with no way to cool the rears (they get HOT!) it is what it is. With Amy and I double-driving the S550 in warm weather, it puts a heck of a heat load on everything. Out of 7 cars in TT3 I was 5th fastest Saturday, and the only one on street tires. There was a LOT of traffic and I fought all day to move up the grid. Frustrating, and I never got a clean lap that day due to heavy traffic and tourists.


        In Time Trial group we often get some folks who some of call Tourists. This includes anyone running in TT without a care for the actual TT competition going on around them. See, we often get W2W racers who pay an extra fee (about 50% of the normal entry fee) to be able to jump into TT sessions for "practice laps". They could be super fast cars, but without a previous TT session, they have to start at the back of the grid. The really fast cars then blast their way up through everyone and muck up everyone's laps. Another type of "Tourist" is when a TT drivers take passengers in the TT group. This is somehow allowed in this region, but it is something I don't like to personally do - since TT drivers are allowed to run in HPDE4 group it is always better to take students or riders along there. These TT Tourists might start in the back and drive fast thru the field or worse, or start in their grid spot and drive slower than normal. This REALLY isn't the right way to do this, and I need to talk to our TT director and NASA Region director about working out a change. With 63 cars in the TT group it was crazy crowded.

        I had one Tourist in a prototype pass me in the esses, when I was on a hot lap, and he almost body checked me - so I drove off track and over one of the BIG curbs to avoid a collision. Bent a wheel, really torqued me off. Nothing seems to happen to these guys even when we complain about it. I think Time Trial competitors are put somewhere lower on the list of priorities than W2W racers - even in the TT sessions. We had 63 cars run in TT that weekend, often all in the same session - which was massively over-crowded, which led to crazy traffic. But I digress.

        In this session this same prototype Tourist passed me in the same esses - and I had to drive over a curb to avoid him!

        I am sure there are some things I needed to apologize for - and I did, in person, to two TT drivers. There were a couple of folks who I held up and another who I passed "briskly", likely in frustration. With plenty of power and brakes for the straights, but lower cornering speeds than "slower cars" on Hoosiers with aero, I was often "that guy" holding up "slower" cars in some corners. I tried very hard not to be.

        It took me all day Saturday and even into Sunday to move up the grid to be in the "right spot" where I could get a clean lap without holding up someone or being held up by cars gridded ahead of me. I tried to not blast by a slower car right before a series of corners, and instead waited until a straight and get them under power, or right before a straight and get them under braking. This car stops well and eats up a straight better than most, but the cornering... not quite up to Hoosiers+Aero level yet.


        On Sunday I was gridded around 20th and in my first session, but still moving up and down the grid depending on my times and others'. I ran my best lap of a 2:32.7 on my AiM Solo timer (2:32.9 on AMD loop) on lap 4.

        Never lost brakes but I got them VERY hot into T12 and T19 where I had to press hard to get the car to make the corner. We measured some rotor temps after a cool down lap of 600°F up front. Yes I am already complaining about brakes with 6 piston 15" Brembos! Just got so spoiled last year running the Powerbrake BBK bits on both my 330 and our FR-S, neither of which ever missed a braking zone or faded - they worked flawlessly, lap after lap. Soon.

        This shot of me is still within "track limits". We were allowed two wheels past the white line that was past the green section?!

        We had some TT guys sessions DQ'd for passing under yellow, and had a number of HPDE and TT cars "have rapid deceleration incidents with stationary objects" (aka: tag walls). It is hard to imagine how you find a wall at COTA, where most corners have 200' of paved run off, but some folks did. Maybe it was the liberal track limits + many missing yellow curbs? Some snap spins to the inside of corners? Whatever the reason it was another reminder that I HAVE STOCK SEATS/BELTS/NO HANS in this car.

        My best lap shown in the video above was far from perfect, and there might have another second or two in a "golden session" with this setup and no traffic or mistakes. As you will see, I missed a 2-3 upshift right as hot lap 1 began - in typical MT-82 style - that cost me a position. Then I had to fight to get that spot back on lap 2. Lap 3 was when a Tourist passed me mid-corner and blew that lap, so it took until lap 4 until I put my best in. Brakes were pretty toasty on that lap, tires were boiling, and I was running out of stamina myself (damn this car needs seats/belts!) Rotor temps were 600F+ after cool down lap.

        Braking into T12 goes from 145mph down to 42 mph, and on lap 4 it was barely pulling 1.0 g sustained there (in previous laps it could touch 1.1g). I think this is just a limitation of the OEM brakes and a lack of any possible rear brake cooling. That's still remarkable, as I was running at 3950 pounds with fuel, driver, and car. Likely the heaviest car on grid.

        continued below
        Last edited by Fair!; 11-21-2023, 10:23 AM.
        Terry Fair -
        2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
        EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


        • #19
          Re: Vorshlag 2018 Mustang GT + S550 Development Thread

          continued from above

          In that first Sunday session I ran my best of the weekend with a 2:32.930. I was almost ten seconds slower the TT3 winner that day, my friend Paul Costas driving the cheateringest cheater buggy C5 Corvette, with max aero and 345 Hoosier A7s!

          Paul demolished the old TT3 track record (5 seconds) and gave me a reality check of where we need to be. His TT3 times were often 1st on the grid, when the TTU classed Ginetta didn't show up.

          This Ginetta prototype with LS power was FAST AF! When it was on track, get outta the way - 2:09s!

          Costas was beating all of the TT2 and TT1 cars for much of the weekend, until a few TT1 cars stepped it up. That's a C5 Z06 at 2900 pounds and only 288 whp... "allegedly". Whatever the case, to run a 2:22.915 lap he had to drive the wheels off that C5.

          Its nothing radical - just a gutted C5Z with some big Hoosiers, nice brakes, good suspension, and aero. Sure, it has some hidden prep, but it looks like a sow's ear and yet it cleaned everyone's clocks. So... don't judge a book by it's cover! This is a fleet car at G-Speed that you can rent and drive at MSR-Cresson.

          Amy got faster all weekend after I coached right seat with her in 2 sessions. It was nice to see my three other students improve as well. My Sunday 2 sec improvement pushed me up the grid and into 3rd in TT3 class, only 1.3 sec off of 2nd place. Does 3rd place seem like a weird thing to celebrate? Did I choke? Drive poorly?

          I drove my ass off and happily took that 3rd place trophy, got on the podium, popped the cork, then drank ALL the champagne (2 bottles!) that hot afternoon! I was just ecstatic to be able to sneak my way into 3rd place on street tires - in a fat ass street car running against a bunch of race cars with aero. Damn right I was happy.

          Of the three student cars I rode in - E92 335i, S550 GT, and 6th gen Camaro - this 6th Gen Camaro 1LE above was by far the most impressive. HPDE1 student driving it in bone stock form was really hustling around the track. We did a 26 minute long session and the car never gave us any grief - brakes, fluids, tires stayed cool in the heat of the end of the day (88°F). I suspect this car on these MSC2 tires could have given our 2018 GT a run for the money... it was quick. Owner said it does gobble up consumables at 3600 pounds, just like the Mustang does. But with so many coolers it doesn't overheat.

          Our car was getting into "limp mode" after just 3 laps - it happened twice to me on Saturday - from high oil temps. Amy ran 4 sessions, I ran something like 7. We would use about 5 gallons of fuel per session but no oil was consumed.

          Even having to deal with massive number of cars in TT and the Tourists, it was still a hugely fun weekend. 400 entries in W2W, TT and HPDE was a new NASA Texas record. I was really sore - gotta get some seats and belts in the car, because with 1.3g lateral spikes and these crappy seats, it takes ALL of my upper body strength to stay upright, steer, shift, and mash pedals. And we need more brakes. And more power. And more grip and aero! We did OK relative to American Iron - a W2W class with pony cars running that same ratio on R compounds and aero. Our 2:32.9 lap time would have been 2nd fastest for AI on Saturday and 3rd quickest on Sunday. We will keep an eye on the AI lap time comparisons, like we did on the S197 when we ran TT3.

          With engine oil temps spiking after 3 laps we need to look at a better radiator + oil cooler upgrade soon. Trans and diff are silently boiling as well, I fear. Lots to do.

          TRACK TEST #8, SCCA CLUB TRIALS, MSR-C, MAY 12, 2018

          So for the previous 4 events we have been chasing a noise, that is obviously a parts issue. We went to this event in the Mustang to try to verify if we had it fixed, and also to see if we could find the 1:21 laps again here at MSR Cresson.

          Amy brought her FR-S out just to make some laps. She knew the car wouldn't be competitive on the 215 Firestone tires that have aged out, but it was her last event on this tire set - as we have 18x11" wheels and 315 Rival-S tires going onto this car this week. Wait... what?! You think I'm kidding about adding 4" of wheel and +100mm of tire to each corner? Think again. Can a 2634 pound car with 200 hp use a 315mm tire? We will see soon... just testing the limits of our "big tires are always better" theory. I have a 6 year long build thread covering this car, of course.

          I drove the 2018 Mustang GT at this SCCA Club Trials event also to compete - turns out we had 10 cars in the "Street Prepared" class I got lumped into somehow (SP allows Hoosiers yet I was on street tires??). I ran the Mustang in 3 of the 5 sessions, drove the FR-S one session, and rode along in EIGHT sessions with either students (and I didn't even sign up as an instructor, LOL!) plus coaching over radios in the right seat. Long, exhausting, hot day... here's my best lap.

          The key word here is "frustrating". I ran the same damn times in all three sessions, which matched as my last test here (April 22), but was still a second off our pace using the small stock 14" brakes in March! I have been trying to rationalize why we have lost a second of pace since then, back when we had a ONE LAP WINDOW of usable brakes on the bass-ackward 14" inverted hat, easy-to-overheat base rotors.

          Our S550 Lap Times at MSR-C 1.7 CCW:
          • Stock 2018 GT laps March 2nd, 2018 - 1:31.412
          • After Round 1 of mods, March 10-11, 2018 - 1:21.733 on AiM (1:21.9 on AMB loop)
          • After 15" brake upgrades, April 22nd, 2018 - 1:23.144
          • SCCA Club Trials at MSR-C, May 12, 2018 - 1:23.031

          This consistent 1 second slow-down, two events in a row here, has verified to us that something has been wrong with the car since shortly after that March event. What I haven't been mentioning in this thread are some issues we have been chasing for 5 events in a row - a very persistent noise and a vague handling issue that has been a real bear to track down. Many components have been removed, re-torqued, and even replaced, yet it still persists. We still haven't definitely proved that a part is "bad" but we will know soon when another major component is swapped out. Until then, just know that this consistent slow-down at our MSR test track has not gone unnoticed. Due to some outside factors (shop move, explained below) we haven't had the time or resources to attack this quickly.

          Left: Street Prepared class results. Right: Overall results

          Even being 1 second off the pace from March, we still won SP class with 10 cars, and had the 8th quickest time out of 57 Club Trials entries. But I was still not happy with the lap times. I ran almost the same times in each session, consistently. Session1 - 1:23.079, Session 2 - 1:23.124, Session 3 - 1:23.148 and 1:23.038. Sure, there was some traffic that forced my best laps in the first 2 sessions until after lap 4 or 5, but not on session 3. That time we were gridded by lap times and I built up a gap on the out lap to the 3 faster cars ahead, which yielded 3 clear laps. Tires are still pulling 1.25g lateral in sections, so they aren't totally dead (but they are far from new, after 8 race weekends). I'm driving the same lines, and running consistent times. Something just seems "off".


          Very, very frustrating.

          WHAT'S NEXT?

          I better wrap it up here, as this update has run long. But for once we are caught up on events! We skipped all of the events we had planned to run in June and July, due to obligations every waking moment working on construction of our new shop, moving our business, getting things operational, then continuing construction while we are moved in. Absolutely not the right order of operations, but one contractor was so late wrapping up (8 months late) that it threw all of my plans out the window and put all development work (including this S550) on hold for more than 2 months.

          We have been shipping orders for over a month and the shop is operational, but the '18 Mustang continues to wait patiently while we tackle some higher priority customer jobs that were delayed by the move. Because of this persistent lap time slowdown "issue" we have opted to not run the car again, even when we had a few hours on a weekend available and it was a local event. Until we can "fix" this glitch, it is parked.

          As more systems around the shop come online and customer cars are catching up, this S550 hiatus should end very soon. We have a prototype 380mm/6 piston Powerbrake front brake kit already on hand that needs to be installed and a few loose ends completed before that goes into production. That will need to be tested on track. We also have Sparco racing seats sitting here waiting for install - which we will do with production level seat brackets made with our newly added CNC plasma table. A whole new suspension setup is also sitting by, ready to to be tested (MCS Remote Doubles!) But until then, thanks for reading.

          Last edited by Fair!; 07-27-2018, 11:20 AM.
          Terry Fair -
          2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
          EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


          • #20
            Re: Vorshlag 2018 Mustang GT + S550 Development Thread

            Great write-up and good to see the progress.

            I think your mustang and the red vette were the "most visited" cars that weekend by the folks in attendance. Obviously the red vette did well to put up a new record, but to run a :32 on STREETS with NO AERO is damn incredible.

            I mean, you think 10 seconds is some huge deficit, but in reality, as long as the lap is at COTA, just going to softs is going to net many seconds. Then add fresh A7s and there is another handful of seconds. Then add aero and get your dampers matched to your spring rates (just following you when I was cooling down I could see they are not where they need to be!!)'ll get interesting!!

            See you at nats!!!

            cars and such...


            • #21
              Re: Vorshlag 2018 Mustang GT + S550 Development Thread

              Project Update for October 5th, 2018: Lots to cover since our last post. Due to customer obligations we did not have a chance to order parts and install these updates on our own S550 until the WEEK before NASA National Championships, so we did what say to never do - last minute updates with zero testing before a big event!

              There were also delays due to the sequencing of production testing for some new parts we have been working with, like the Powerbrake 380x32mm rotor / 6 piston Motorsports front brake kit. At the same time we installed a different set of coilovers (MCS RR2) - and we have more sets to test next. We also developed a production S550 bolt-in 4-point roll bar, seat bracket for a Sparco Circuit II seat, installed a new Schroth 6-point harness, and threw on a set of 315mm Hoosier A7s. Most of that was only wrapped up the day before NASA Nats. Yikes!

              But I was excited to get back to COTA - so let's dig into Round #3 of mods to our car, then cover NASA Nationals and the short list of updates after.


              Brakes: for cars used on track, this is the most important system on the whole car. We started with the base model GT, which comes with CRAP 14" front brakes. We then spent some time testing and upgrading the brakes to the 15" PP fronts. Now we wanted to go further...

              Left: Base model 14" front inverted hat brakes. Bad. Right: 15" 6 piston PP brakes were next

              We have covered our extensive struggles with the base model inverted hat brakes. We wiped out brand new OEM front brake pads in just 8 laps, down to the backing plates. Then we tested two G-LOC compounds up front (R8 and R16). With aggressive driving I could still fade the front brakes in one lap. ONE. LAP. It was all the rotors' fault, so we upgraded to the Performance Pack 15" dia 6-piston brakes and new G-LOC pads. With 4" brake cooling, since that 15" rotor isn't made bass-akwards. Those worked much better. If I didn't know any better I would have thought this was "as good as it gets".

              But I do know better. I've been spoiled with Motorsports level brakes on two of my own track cars for the previous 2 years. Our BMW 330Ci got a Powerbrake 340mm x 34mm 2-piece rotor and large 4 piston caliper front kit, shown above. I used the same set of front pads for 2 years - and they were still good for another year!

              Our FR-S has the Powerbrake 325mm x 28mm 2-piece rotors and 4-piston caliper front kit. Still on the same pads 2 years later also. The difference in feel from the best OEM calipers to what these cars have is enormous. Side note: we did spend some time during the 3 month break between these S550 posts working on our FR-S, installing then track testing 315/30/18 Rival-S tires on 18x11" wheels with giant flares. #BigTiresMatter You can read about that in this linked build thread.

              We knew before we even bought this 2018 Mustang that we wanted to help validate a new Powerbrake kit for the S550 chassis. We have worked with this company to develop and test 350mm 6-piston kits on SN95 & S197 Mustangs and C6 Corvettes, as well as our BMW and FR-S shown above. With the weight and power of this S550, Powerbrake wanted to use a larger 380 x 34mm 2-piece rotor kit to go with their X6EL 6-piston Motorsports caliper (shown above).

              There are many benefits to upgrading from OEM brakes with 1-piece iron rotors to Motorsport bolted billet calipers and 2-piece rotors. Caliper rigidity with the thru-bolted construction stays stable with higher temperatures. Staggered bore, stainless, vented pistons can be designed to promote even pad wear (no tapering). The 2-piece floating rotor style prevents coning ("warping") as the iron rotor ring heats up, and the aluminum hat keeps weight down.

              The weight difference can really add up. On our BMW E46, the weight drop for the front Powerbrake kit was 4 pounds, with a MASSIVE increase in caliper and rotor size. On our FR-S the PB kit it was 9 pounds lighter than stock, also with a substantial increase in both rotor and caliper sizes. On this S550 Mustang, the weight drop from the entire 15" PP brake package (14.26 lb loaded calipers + 34.12 lb rotor x 2 = 97 pounds) was 21 pounds going to the Powerbrake kit.

              Left: 15" PP rotor = 34.12 lbs. Right: 380x34mm Powerbrake 2-piece rotor = 24.4 lbs

              A good bit of this weight drop was in the rotors. The 14" inverted hat front rotor was 28.4 pounds and the 15" PP rotor was 34.12 pounds.

              The rotor rings are replaceable, which saves costs in rack consumables down the road. This was us installing a replacement set of rotor rings going on Jamie Beck's ST2 Mustang that has 350mm Powerbrake 6 piston fronts - after a season and a half of racing!

              After the PP master cylinder and booster upgrade, and with 4" of brake cooling forced inside the hat of the front rotors, the 15" OEM Performance Pack brakes worked admirably. But again - I had two other track cars at the time with Powerbrake BBKs, and I knew what that difference felt like. The data logged braking on the upgraded OEM 15" brakes was better than the base 14" brakes, just not stellar. Not what I'm used to anymore.

              One week before NASA Nationals we installed this prototype Powerbrake big brake kit to our 2018 GT. We had to make a custom front brake flex line, but we have shared that info with Powerbrake and it should be in the production S550 kit by the time you read this. We also trimmed up our prototype S550 front brake cooling backing plates, just slightly, so that this can now work with the 15" PP brakes or the 380mm Powerbrake kit.

              After bleeding the system with fresh RBF600 Motul brake fluid I was eager to test these on track, but our compressed build schedule would not allow for a dedicated track test - we'd be testing at Nationals!


              We ran 7 of the first 8 events on the Whiteline monotube inverted coilovers. This was something they asked us to test, as we have a long history working with Whiteline. We had good results and ride quality but by the time we got them on the car and on our website for sale, the deal with their supplier went away, and we had to stop offering that setup. After that we ordered what we had originally intended to use for the long term with Hoosiers - these MCS Remote Doubles, which we call the RR2 model.

              We paired these dampers with Vorshlag S550 camber plates, some of our prototype spherical rear shock mounts (more on that later), and one of 3 tested sets of Hyperco springs we spec'd for this application. The spring rates we chose are our "middle" set: 600 #/in F, 750 #/in R. We call this our "GTS" rates, with the GT rates being softer and GTR stiffer. We ran the softer GT rates (400 #/in) on the Whiteline set and still noted some body roll and dive, so we wanted to see the difference on the MCS set, which would only be amplified by the upgrade to stickier Hoosier A7 tires.

              Unlike the inverted Whiteline and Ohlins kit for the S550 chassis, the front MCS strut is a traditional (non-inverted) 22mm shaft monotube with the Rebound knob at the top of the shaft and the Compression knob on the remote canister. The rear damper is in fact an inverted setup, also using a 22mm shaft monotube with the Rebound knob near the lower "T-bar" mount and the Compression knob on the remote. This was the first inverted rear MCS we had run in anger, and we have passed on a few suggestions that MCS has already incorporated into their S550 shock.

              The installation was pretty straight forward, but as you can see the strut stem and knob would be pretty close to the edge of the strut tower opening - and in fact will limit camber travel. The Whiteline was an inverted front strut, which has a super short upper stem and the knob at the bottom, so that constraint wasn't an issue. The top mounted knob on the MCS makes for easier access, but the S550's small strut tower opening (only 1.8 inches - more on that below) made it to where we left the knob off for the COTA event (we ran out of time to modify the towers). I was able to make Rebound adjustments with the small Allen wrench supplied, using the holes in the upper hex portion of the adjuster.

              These went on the car on a Wednesday, and we loaded up for our trip to NASA Nationals on Thursday night. To call this "rushed" would be an insult to the word "rush", hehe. No major issues noted in the two test drives I took in the car that day, rode fine and we set the knobs to about "halfway" on rebound and compression both.


              Most folks know that we make roll cages. For a dedicated race car that's all I want to have protecting me anymore. Of course our 2018 GT is very much a dual-purpose street/track car. For that situation a 4-point roll bar makes for a safer setup on the street (no rooftop door bars near an un-helmeted head), yet still gives us some rollover protection and a GREAT place to hang some shoulder harnesses from, for use with a fixed back racing seat and 6-point harnesses. I have been really missing those safety items in this car.

              In the past we have used the Maximum Motorsports 4-point roll bars kits for the S197 chassis, with some key options picked. But its no secret that I haven't been too happy with the bolt-in roll bar options available for the S550 Mustang chassis (and Maximum doesn't have one for the S550, as of this writing). We looked at 4 different options and found things we could improve on all of them. If it looked like we could improve on the options out there we agreed that it could be a new production part from Vorshlag.

              We started by removing the front and rear seats and all of the rear interior panels. I wanted a "clean slate" to look for good factory bolt holes to key the roll bar off of. We also looked at NASA Club Codes & Regulations for material requirements, bar routing, angle suggestions, and other engineering aspects for W2W roll cages (that we applied to the "half cage" that we built).

              After copious scraping of seam sealer from some key areas, Jason (engineer), Myles (new engineer/CNC guy), Evan (fabricator) and I all brain-stormed some ideas using the best methods of attachment we could find in the back of this chassis. I had a few requirements that I would not budge on: a fully welded assembly (no post-delivery welding!); a diagonal in the main hoop; use 1.75" x .120" wall DOM tubing (not drag race tube specs); the main hoop kept tight to the roof; and a recessed harness bar for use with taller drivers.

              After some iterations in cardboard, I was happy with the landing plates for the main hoop and rear downbars (the "4 points" of this roll bar design). We transferred the cardboard templates into CAD files, then using our new CNC plasma table, cut out plate steel in two thicknesses over 4 revisions before we had the "base plates" and mounting plinths built to our liking.

              Unlike the S197 chassis that has a replaceable corner section for the main hoop to land, we made these that bolt into the chassis and nest over top of the OEM bits here. This puts the main hoop at the optimum location for the tallest part of the roof, close (but not TOO close) to the driver, and as wide as possible.

              continued below
              Terry Fair -
              2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
              EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


              • #22
                Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                continued from above

                Once the main hoop was bent and trimmed it was fit snugly into the car (with the interior roof panel in place - it's touching). Then the diagonal, harness bar, and rear down bars were tack welded in. It was removed and final TIG welded. The main hoop was routed to clear the OEM shoulder harnesses, so a dual-purpose car (like this) can use the stock belts for street use. Much safer that way.

                The completed roll bar was installed for the final time before we moved to other systems. It sits on the rear seat bulkhead and just rolls back onto the rear seat belt mounting studs and holes. Two holes are drilled in the chassis at the rear down bar mounts (4 bolts per plate) and we could have slipped in the rear interior panels and given them a trim, but I'm going to see about that soon.

                No, there are no provisions to install the rear seats or seat belts. Why? Because that is silly - nobody should EVER ride in the back seat area with a 4-point roll bar installed inches from their face. As you can see 62 pounds of back seats, belts, hardware, and interior panels came out and about 58 pounds went in with the 4-point roll bar. A net loss of 4 pounds while adding some safety.

                At least now I can have some place to mount shoulder harnesses, and feel safer in this car than before. We ran the bar in raw steel for COTA but pulled it out when we returned for powder coat. Next up in our last week thrash... adding a racing seat!


                If you have read my posts on other build threads you might know how much we dislike most of the "bolt-in" seat bracket kits out there on the market. I've yet to see one that I really liked. They tend to be weak, sloppy/floppy, poorly fitting messes. I talk at length about seats and mounting challenges in this forum post.

                The base "300A" interior GT 6-speed we got stickered for $36.6K retail. Of course the base seats are COMPLETE GARBAGE, and we thought about upgrading to the "$1595" Recaros. Those work fairly well and would be a great option - if they weren't $10K! Yes, go to the FORD website configurator or click the top right pic to see this: you have to upgrade a bunch of packages to be able to buy the "$1595" Recaro seats, which is how it becomes a $10,095 seat upgrade!

                Remember back to my original post about why we purchased a base GT? We wanted to avoid a bunch of useless fluff that would be replaced with better parts in our quest to make the "GT3 RS" version of the S550 Mustang. For less than the "$10,095" price for Recaros, we can damn sure pay for some fixed back racing seats, real harnesses, and a roll bar - just like the GT3 RS has.

                pics of the seat brackets we made - with production in mind - for the late model Audi R8

                This time instead of fabricating the brackets one-off we wanted to make a production worthy unit, like we did in this Audi R8 V10 last year. For that car we made a 100% bolt-in seat bracket that fit the carbon tub of that chassis, had provisions for the lower 4-points of a 6-point harness, had a bracket to hold the OEM seat belt lower buckle, allowed for the use of a slider, and made the seat install easy.

                That setup worked VERY well in this 2017 R8. Weirdly enough the car was wrecked HARD at COTA later that year, and our harness bar + seat brackets + harness mounts held up perfectly. Guy walked away without a scratch. #CrashTested

                With our CNC plasma table we could make the S550 "production seat bracket" version 100% in-house. Problem was... the first two iterations didn't look clean as the Audi version we made. Super heavy duty. I mentioned what a time crunch we were in - #NASAchamps was just days away! We had to make this version work for the short term, even if it was a little ugly. Plenty strong and rigid, just not production ready.

                The floor in the S550 has some funky angles, and we used too thick of a piece of steel on this iteration. The prototype worked well, even if a bit on the heavy side and time-consuming to weld up. I could fit my 6'3" frame inside with CRAZY room to the headliner, and the slider allows Amy to move forward as much as 18", so she can drive as well. I'm sitting at least 3" lower than stock. We will re-design this bracket and show the production version later in this build thread.

                We used a single Sparco Circuit II seat with a full halo. Scroth's new for 2018 "FIA 2016" rated belts in red were chosen. We went with the 2" belts to make it easier for HANS use. The seat fits very well, slides back for taller drivers and forward for shorter, has no movement outside of the slider's own, and made for a much more comfortable "day at the office" pulling 1.5 g loading with 315mm Hoosier A7s!


                We borrowed a friend's Hunter alignment rack and Evan aligned the car to get -3.5° front camber and -2.2° rear. We were in such a rush we didn't print a sheet.

                We weighed the car earlier that day, right as the seat and roll bar install were wrapped up. We didn't install the other seat because of time constraints, but needed a weight and a dyno to figure out if we would run in TT3 class, and if so how close to the power and weight limit. 3607 lbs with no driver, 3825 lbs with driver and 3/8ths of a tank. We would always run the car full of fuel, which would add +50 lbs, even after some laps of fuel burn.

                I was able to get into the busy schedule for a handful of dyno pulls at True Street Motorsports the day we were loading up. Richie made 5 pulls and he noted quickly that the car was hitting a 145mph speed limiter, due to the lower speed rated base model tires our car came equipped with. We had never hit 145mph on track (I just touched that speed at COTA in May, on the back straight) so I didn't know this existed. NASA rules require that the dyno tests are done in 4th gear, which on the 2018 GT's "MT82-D4" transmission is now 4th (from 2011-2017, 5th was 1:1).

                That's why the dyno stop at 6750 rpm in 4th, due to the speed limit. Without re-programming the stock tune, it was what it was. We double checked the NASA dyno procedures and we decided to stick with this, as this is how the car could be dyno'd at Nationals (and they DO dyno a lot of cars there).

                Dyno certification form, Dyno avg whp form, NASA TT classing sheet

                With peaks of 443 whp STD / 435 whp SAE, using the NASA average dyno procedure calculates to 417 whp average. I ran the numbers, filled in our TT classing sheets, then ran the numbers again. We were safe for TT3 at 3825 lbs and 417 whp, but only just. To compensate for any scale mistakes or dyno errors, we claimed 423 whp avg (+6 whp) and 3855 lbs (+30 pounds). This comes out to 9.11:1 pounds per whp, and with our modifiers (+0.4 for stock aero and +0.5 for 3801-3900 pound race weight) we came to 10.01:1, p-to-w. We ran even heavier, crossing the scales after every session at 3860-3876 lbs at Nats.

                We ran out of time to have the 315/30/19 Hoosier A7 tires mounted to our only set of 19x11" wheels (for now). So we tossed them in the trailer and hauled ass down to Austin Friday morning, hoping to get unloaded and on track by 4:45 pm that afternoon. We would play it by ear with the weather, possibly running some of the first sessions on the RE-71R street tires... because it was raining. HARD. And the forecast showed much of the same.

                NASA @ COTA - May 2018 Recap

                As a quick refresher, back in May we ran our 2018 GT at COTA with NASA. We did that event on the Whiteline coilovers, RE-71R tires, 15" PP brakes, and the track limits for that event were quite open (the large F1 curbs on the outside of T11, T12, T15, and T20 were missing). I ran a best lap of 2:32.9, which I was fairly happy with. That took 3rd place in TT3 class at this Regional TT event, losing to Paul Costas in the G-SPEED prepped C5 Corvette by a massive 10 seconds.


                As crazy as that sounds, the 2:32 lap time was actually pretty good, and would have been the P2 qualifier in the American Iron W2W race field (AI times are something I've always compared our Mustang TT3 times to, as they are all pony cars with similar 9:1 power to weight ratios, full aero, etc). We saw high oil temp problems, traffic/tourist issues, and the street tires were holding the times back a bit, but I finally had brakes that worked - where I saw 1.2g braking into T1 and 1.0g into T12 (after back straight). Cornering was 1.1-1.25g lateral on the 200 treadwear tires.

                NASA NATIONALS AT COTA, SEPT 14-16, 2018

                After loading the Donkey and the Mustang into the trailer, Amy and I blasted down to COTA on Friday morning. We got there around 12 noon but the off site registration had closed, so we wandered into the "A" lot out front. The weather had been bad all week during testing and not many dry laps had been taken until that Friday morning. We didn't pay ~$1M for Thursday or Friday test and tune sessions, and instead would rely on the 5 or 6 TT sessions to setup and learn the new suspension/tires/brakes, running Friday night through Sunday.

                Parking was a bit of a thing, with 500+ racers and 70 in Time Trial. The garages sold out ages ago at $2000/per, and even the lower paddock lot was full. So we parked out front in Lot A, near the kart track, outside of the track.

                the distance to the paddock / grid area from Lot A was over a mile and a half, but luckily we had brought the Donkey - our recently restored Taylor Dunn pit vehicle. We drove many, many miles over this 3 day race weekend in the Donkey, staying dry in the rain and honking at everything that moved. Hauling fuel jugs and tires or taking passengers. A donkey is not known for its speed, but it sure beat walking!


                With zero testing I was to go on track at 4:45 pm for the TT Warm Up. Raining pretty good, on the street tires. As I drive to grid I realize we have the rear ride height set too low and it's bottoming badly in paddock. Went out anyway, trying to move up from my 64th spot on the 70 car TT grid (they gridded us for the first session based on when we signed up?!) Passed over 20 cars in 3 very wet laps. Car bottomed out a lot, ran a 3:00 lap... terrible.

                That night we had some major changes to make. In the dark. And rain. Forgot to bring a good floor jack and nobody around us had one, so we went to a local Harbor Freight and yelled "Sell me your finest jack, good sirs!" Got back, raised the ride height a little at a time until we got about an inch and a half of rear bump travel. Big thanks to competitor Paul Costas who helped us with these ride height changes! Drove each iteration around the very bumpy paddock roads and it was not perfect, but better.

                Snatched the wheels off, took them using the Donkey over to Hoosier, who said they would change them first thing in the morning at 7:30 First in line.


                We showed up early at Hoosier (7:15), nobody around. Came back at 7:45, and now we were 5th in line. Another TT meeting at 8:30, then on track at 10:10. We were waiting impatiently at Hoosier and they had all 4 tires mounted and balanced by 9:40. Hauled back to Lot A and went to mount the wheels and tires. "Only 10mm wider" than the 305mm tires we had on there? Should be no problem.

                continued below
                Terry Fair -
                2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                • #23
                  Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                  continued from above

                  Big problems. Tires won't even turn, hard stop against struts in front and e-brake cables out back. These 19" Hoosiers are fully 1" wider per corner. YUGE! You can see that in the stack of 4 Hoosiers vs 4 Bridgestone tires, below left. We had to do a mad scramble and add some random 3/8" and 1/2" spacers behind all 4 wheels, which was all I had in the trailer.

                  Battery powered impact dies on the 7th wheel change, so we're spinning these lug nuts onto super long ARP studs by hand. We had NO TIME left. I jump into the car (sans driving suit), drive over to paddock, and make it at the 5 minute warning, when they are about to close grid. CLOSE!

                  I managed a decent first session, ran a 2:37.339 lap on a moist track, only a tenth behind Costas. Good time, moved me WAY up the grid.

                  2nd session was pissing rain as we went out, I was 24th on the grid, but I went out on the A7s anyway. then I passed everyone ahead of me. I had a blast - this was my favorite session on track of the weekend. Had a 2:51.0 best wet lap. I love racing in the rain, as its when I have always done my best in autocross and track driving. No tread on these A7 tires, but it was still 10 seconds faster than the street tires on Friday. Won't bother bringing street tires as "emergency backup" rain tires ever again. Either bring Full Wets or don't bother.

                  3rd Saturday session was finally not wet - our first dry session of the weekend, and I ran my best so far. I put down a 2:30.333 lap, which was 11th quickest of the entire 70 car TT field. I was finally quicker than we ran in May here on street tires (*which had radically different track-out on 4 corners). That moved me up into 3rd place out of 10 in TT3 by then. Costas in the G-SPEED C5 ran a 2:24.948, provisionally had 1st in class, but his time was DSQd (blew dyno). Schotz was quick and really in 1st with a 2:27.559. Our customer Adam B in his EVO X (we had done a lot of safety work to thisd car) was ahead of me in 2nd by 0.05 sec with a 2:30.293. We were all bunched up, other than Costas, but he had dyno problems...

                  At this point I felt pretty good about our performance, so we left the car alone and went to dinner at Javi's with Adam and also Danny Puskar from G-LOC brakes - where he had his first ever taste of Mexican food. Like... ever!


                  Sunday the Championship races were wrapped or wrapping up for the W2W classes. TT had 2 more sessions that counted, but those were each in a "split group" with the faster half of the TT grid in the A group then the slower half of the field in the B. Less traffic with half as many cars on track, and by this point the field had pretty much sorted itself out by times / placement. It was much easier to get clear track this way.

                  After our 7:15 am TT meeting, I went out in the 8:20 am A group TT session, where it was 77°F, overcast, and dry - our second dry session of the weekend. I spent Lap 1 behind Adam's EVO and and put down a 2:28.980 lap (shown in the video above). Adam started pulling away from me on lap two but I slowed down a half second; he ran his 2:28.4 best. In the B group some TT3 BMW threw down a 2:27 and jumped up to 3rd place, outta nowhere... so I fell to 5th and Adam to 4th.

                  The next session was dry but considerably warmer, and almost everyone slowed by about a second. The "golden session" was that Sunday morning early one. That's when 95% of the TT racers put in their best time.

                  My 5th place time in TT3 would have been 3rd place in TT1 or TTU, faster classes that just had a little less depth in the field. Oh well.

                  Podium pics from TT - congrats to all trophy winners!

                  We went to the award ceremony and congratulated everyone who got a trophy. I don't think any TT records fell - again, everyone was faster back in May. We packed up our paddock spot, loaded the Donkey and the Mustang into the trailer, got on the road by 3:30 pm and were home by 8 pm.

                  Results Analysis, Issues, and Lessons Learned

                  Driving in the rain on A7s isn't terrible, unless it is POURING rain. A pit vehicle with a covered top is highly desired at wet events! #TheDonkeyRules

                  Oil temps were a real problem all weekend, even more than we have seen before. In the wet I could do 4-5 laps before oil temps got into the red and the car went into limp mode. In the dry sessions it was rare the car could go beyond 2 hot laps. I was taking precautions and not letting the car idle in grid, taking a super tame out lap, and only giving it full throttle and rpms on the hot laps. We have already ordered a new radiator and oil cooler, plus a suite of analog gauges (see below) to fix this.

                  The Powerbrake setup was phenomenal all weekend. Super easy to push the car in the wet or dry. Best aspect of the car, even slightly better than forward acceleration, which this motor provides plenty of. Coupled with Hoosier A7s there are several 1.4-1.5 g stops into T1, and 1.2-1.3g into T12. Lateral grip was 1.3-1.4g when I loaded the car up in corners.

                  Forward acceleration was a little hampered here by the unusual trans+rear gearing - I was never quite in the right gear. 2nd was a bit much and could easily haze the rear tires out of T20 and T11. 3rd was a hair sluggish in some corners. Didn't top out 4th on the massive back straight (touching 146 mph), which is the 1:1 gear, at our fastest track on the calendar?! This MT82-D4 gearing is wacky and we will obviously change the rear gears to a 3.73 or 4.09 final drive soon. We will run the calcs for the tire heights we use and pick the best ratio and re-gear.

                  The rear suspension was bottoming out in 4-5 corners per lap, even after the ride height changes made Friday night. So I had to drive around apexes and avoid some of the bumpiest sections - that cost me some time. And of course the track-out on T11, T12, T14, and T20 were massively different from the May NASA event, which easily cost us 2-3 sec per lap (most racers that ran both events noted this delta). We could still track out of T19 as much as we wanted, which I always did...

                  video of tracking me out of T19 behind Costas... maybe that was a bit much, LOL!

                  Traffic was pretty ugly for the first few wet sessions, as some of the slower drivers in faster classes held up cars behind them. This TT1 classed Audi was particularly bad about blocking, and held me up on no fewer than 3 sessions. Driver was just not aware of anyone around him, at all, and dozens of us complained about him and a few others in the driver's meetings. This sometimes happens at Regional events, but to see drivers with so little situational awareness at a National Championship was odd. Some drivers very nearly got an event DSQ from this stuff.

                  I like the fact that National TT Czar Greg G. held 5 separate TT driver's meetings. It let us give feedback on issues like these blockers, rules situations, flag infractions, and dyno questions. I liked the meeting frequency. Very much favor of this format rather than the "one meeting for the weekend" format most NASA regions run. There were probably 10 people that got session DSQs from our feedback in these 5 meetings - all of which were well deserved. Greg always took roll, so if you missed a meeting and didn't send an approved proxy - you also got a DSQ from the previous and/or next session.

                  The National TT rule of "no passing on the first hot lap without a point by" was a little strange, but we got used to it. Some folks had trouble with the dyno but we weren't fast enough to get called up, so it didn't effect us. There were two scales and we were weighed after every session. I had issues on the left scale twice. It read my car 200 pounds light once, 100 pounds light another time. On the right side scale it was always 3860 - 3876 lbs, depending on fuel load, which was on the money. We learned a long time ago to only run this car at a FULL tank, which helped with ballast as well as prevented fuel starvation on left turns. With Hoosiers this was more important than ever.

                  My first lap was usually the quickest, as tires would get just a tick slower after one lap (normal for A7s). Obviously the 12" wide "315mm" Hoosiers didn't fit the car as we had it setup, and we had to scramble to make it work. You can see that clearly in the "as measured" tread width and section width numbers below for the RE-71R and A7. We've since fixed the spacer/camber issue (will show later in the thread) but I should have invested in another set of (18x11) wheels long ago, and test fit the Hoosiers at the shop (note that the 18" version of the 315mm A7 is $86/tire cheaper than the 19", below). There is a way to fit these 12" wide tires without spacers, but not without a lift and power tools. We have two more sets of race wheels ordered now (MOMO).

                  Of course setting up a car with all new EVERYTHING at a National Championship race weekend is the WRONG WAY TO DO THIS. Again, customer obligations forced my time table back to the 11th hour. Which meant I was still learning and tweaking the new setup in the handful of dry sessions we had that weekend, but still managed to close the gap to the #CheateringestCheaterBuggy C5 by 5 seconds, down from a 10 second gap from our last match-up in May.

                  The C5 that won TT3 was 2650 pounds (2880 with driver and ballast) and made about 288 whp (tuned down from 480 whp) with a custom "flat power" tune. Costas was often the quickest car on grid, and he put down some damned fast laps. G-SPEED had done some major improvements (Penskes, Brembo Motorsport brakes, rear diffuser, moved up to 335/345 A7s, new motor, magnesium C7Z06 subframe, and more) to this Corvette, dedicated testing and data collection at COTA, and we still caught up 5 seconds to their times. G-SPEED had the motor for this and the TTU winner built by HPR (which I am a small part of) and Costas is a good friend of mine, so I was happy for them.

                  That 5 second catch-up to Costas was my stretch goal for this event, and we managed to do that as well as outpace the entire American Iron grid (the fastest AI racers ran high 2:29s); they were the closest cars to our Pony car, at this event.

                  American Iron Champ Race results lap times

                  At one point our Mustang was 10th quickest on grid out of 70 in TT, in what I am fairly certain was the heaviest car on track, and one of only a handful of street cars around.

                  It was a VERY busy weekend here, as we had a crowd at our trailer at almost all times (customers, dealers, vendors), plus we had to park 1.5 miles away from grid, so there was significant time spent going back and forth to drive and for meetings. Next year we will register early and get a GARAGE in the front straight paddock - damn the $2000 cost! I missed just about every W2W race I wanted to watch, being stuck out in lot A.

                  Adam Baltutis in his TT3 EVO X (at left) and me throwing silly "VM" gang signs in front of our Fat Bastard! (on the right)

                  The new seat and harnesses worked GREAT! Wish we could have done this sooner. Even with higher g loading my back and arms weren't on fire, like they normally are after a long TT weekend. I wore my race suit in every session except one (where I barely made it to grid, jacking with the Hoosiers). It was hot and humid most of the weekend and I definitely got hot in my suit, so we need to seriously think about a cool suit (note the hoses coming out of Adam's suit, above - we added a cool suit setup to his car). If we add more power we will need the ballast anyway.

                  continued below
                  Terry Fair -
                  2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                  EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                  • #24
                    Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                    continued from above

                    Amy was my rock over the 3 day Nationals weekend - she could have driven on Team Vorshlag but due to the limited number of dry sessions she let me drive them all. She kept me hydrated and fed between sessions, helped with tire changes, took pictures, everything. The weather was a constant challenge but everyone had to deal with it, and we got our two dry TT sessions. There was a little drama, and a car that was handicapped a bit (oil temps & rear shocks), but I was damn happy to run a 2:28 lap in a heavy car, with a bone stock engine, AC, zero aero, and that was still street legal. I used the AC on many occasions!

                    We had a good time running this National Championship event, and I look forward to running with Texas TT3 guys like Costas in the G-SPEED C5 and Adam in his EVO again next season.


                    We got back from COTA with the big spacers on, and the tire poke was KILLING me. Why does any amount of tire sticking past the fenders matter? Well in reality its not that big of a deal - if you have sufficient clearance at full bump travel. The #CheaterC5 had gone to 335mm fronts (from 315s) between the May and September events, with just cut fenders, and it was still plenty fast.

                    Left: #HellaPoke! Right: At full bump travel and loaded in a corner, the outside tires were very close to the fender lips!

                    But having the tires sticking out past the fender lip can cause tire damage when going over a big bump. Luckily when our car loaded up in corners, the sloppy rubber suspension bushings loaded up and pushed the wheels inboard enough that the outside tires it just barely cleared the fenders (see above). Man it was close!

                    Still, going down the straights with a spinning tire sticking out in the air stream, especially the fronts, adds a lot of drag. We often make fairings that blend into the flares/front cover (or even just basic "tire walls") to cover up the leading edges of the front tires - like we did on our TTD/TT4 BMW E46, above. That is something we need to address on the S550, eventually. We may or may not do big aero on this car...

                    Changing from 1/2" to 1/4" spacers made a big difference, above

                    I asked Evan to look at the rear E-brake cables (which was where the rear tires touched inboard). Those got bent out of the way (just a few gentle taps with a 5 lb sledge) and now we have 1/4" more inboard rear room (see below left). Then we swapped out the front spacers to smaller 1/4" thick units, and the #HellaPoke is much removed (see above).

                    Up front was a balancing act between the strut-to-spindle slotted connection and opening up the strut top hole. The strut brackets almost always has one slotted hole, especially on aftermarket coilovers. We will show how to "fine tune" this interface for the ideal tire clearance + camber in the next thread update. With these splined spindle mounting bolts, it is tricky (above right), but possible.

                    I'll show more of the strut tower opening next time, but we made a new series of tools that we will sell soon for the S197 and then another for the S550 towers. These bolt in place of the top mount and line up a hole saw.

                    We chose a 2-3/4" hole saw and cut the towers on my 2018 GT here. This allows a good bit more camber travel as well as caster travel. With the MCS RR2 struts in place we can kick the top of the strut a lot more inboard now. This allows the strut-to-spindle junction to push outwards for more inboard wheel room to the strut.

                    We took the Hoosiers off the 19x11" wheels (above left) - they looked great and should give us another competitive weekend or two of NASA events, with careful tire management. The RE-71R tires (above right) were re-mounted to the same 19x11 wheels again. I had them flipped relative to the wheels, and after 7 events/weekends there is plenty of rubber left. Still has a good durometer number, too.

                    We have a few street tire events lined up (to test the Ohlins coilovers we just added), then a NASA event at the very end of October (back on MCS RR2s). By then we hope to have our new MOMO wheels (Heritage 6 in 18x11, above left, and RF-20 in 19x11, above right) on hand, to be able to swap tires and wheels more easily. The plan is move (the next new set of) Hoosiers to the 18x11 set and keep running 305/30/19 street tires on the 19x11 wheels.

                    The brakes looked great after COTA. Again, braking was the BEST thing about the car at Nationals. Could always pass other cars into a braking zone, if I needed to. Made a LOT of passes T1, T11 and T12. Temp paint on the rotors and temp strips on the calipers showed that we were in the right heat ranges. The Powerbrake PB13 front pads had good bite without upsetting the ABS tuning in the wet. Going to keep these going on the front for a while. Rears are R16, very aggressive compound, but it's working.

                    We have another set of dampers on the car right now, Ohlins R&T, for a track test and some other events in the next month. The MCS dampers are going back on the car for a NASA event in late October, with a few small tweaks to the rears. Will share more of all of that next time.

                    Last but not least, we did an oil change. We went from Motul 5W50 to 0W40, at Motul's suggestion. We will try this at our next track event to see if there is any change.

                    WHAT'S NEXT?

                    There are a number of items we have shown in this build thread that will soon go into production. Our front and rear S550 tow hooks. The 15" PP / Powerbrake 380mm brake cooling backing plates, and the 2018-19 GT brake inlet ducts.

                    We will also heavily re-design our S550 seat bracket kit, and we are coming up with the costs for the 4-point roll bar. Just got that back from powder coat and its about to go back into the car.

                    A number of things have kept us from making some of these new S550 parts. Mostly suddenly high materials prices - aluminum and steel costs are SKY HIGH right now. I'm losing $1000-2000 a month covering these increases, but I don't want to raise our parts prices yet, since the panic over the tariffs should be temporary.

                    We have a lot of other parts coming to test. An S550 oil cooler from Mishimoto will be here later this week and their S550 radiator soon after. Auburn sent us their new 34-spline differential to try, so we will put that into a new S550 aluminum housing with a new gear ratio (3.73 or 4.09) very soon.

                    Lastly I have a set of 3 analog gauges coming to monitor engine oil, diff and trans fluid temps. I don't trust the OEM data for any temps. These 2-1/6" diameter, 270° sweep, stepper motor, electric gauges are going into a Ford Racing M-6304GPOD-A housing (Boss302) for a dash mounted setup. It should look like the image above. Will show the install of all of that next time.

                    We have a lot more plans in store for this car over the "winter" and we will post up again, shortly after the final NASA Texas event of the year. There are many more events for 2018, too. I definitely need to redeem myself after the dismal showing I had at NOLA with Optima back in April, but having functional brakes might help!

                    Thanks for reading,
                    Terry Fair -
                    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                    • #25
                      Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                      Project Update for December 29th, 2018: Plenty to cover over in this, my last forum build thread update for 2018! Since the last entry 2+ months ago, we have done 3 more track events. I will cover the last NASA Texas TT event at NOLA (late October), a dedicated test day MSR-Cresson (November) where we tested the Mustang on Hoosiers and RE-71Rs, and an SCCA Club Trials at MSR 1.3 (December).

                      Several of the prototype bits we showed in previous posts are now in production, including our S550 rear tow hook, the 2018-19 GT front tow hook, S550 front brake cooling backing plates and 2018-19 GT front brake inlet ducts - with more in the works. We even released a new S197 part! Our new shop setup (we moved in June) and some new equipment is allowing us to turn out more new products quicker than ever before.

                      We cover the installation of the S550 Ohlins R&T kit. Now that I have tested these on the street and at 3 track events, with Hoosiers and street tires, I have some good first hand opinions of this Swedish built setup. We will also show a trick for adding rear tire room out back for the S550. A 3 gauge pod install will be shown, plus the Mishimoto oil cooler install - which made a huge improvement to the track abilities of this car.

                      We will show what 9 track weekends have done to our original set of 305/30/19 RE-71R street tires. After seeing this, I don't feel they are as delicate as some others say, but we have been very careful how we utilize these sticky 200 TW tires. #NoStreetDriving

                      We have also put together a proposal for sponsoring a new Street Tire Time Trial series within NASA Texas for 2019, which I will discuss briefly at the end. Excited to make this happen and hope it brings more new people to come try out Time Trial. Let's get started!


                      So there are a lot of opinions of what tires and wheels can "fit" the S550 Mustang chassis under stock fenders. We have sold 12" wide wheels to S550 guys, but we always warn them that the tires will stick past the fenders (aka: poke).

                      This is easily defined as a "past the fenders" fitment, but people still like to argue

                      And yes, 12" wide wheels will poke past the fenders on the S550. Ask online, however, and a dozen folks will chime in that they have seen people running 12" wide wheels and 335mm tires "with no problems". Again, these folks live in the KINGDOM OF POKE. We have not seen a 335mm tire that actually fits under the unmodified fenders of a Mustang GT. If we felt like we could fit a 335mm tire under an S550 without cutting or hammering, we would have damn sure done so over the past 4+ years.

                      Then there are the "Real" measurements of some tires. For instance, the 315/30/19 Hoosier tire is one big fella, with 12.3" of section width. It barely fits on an 11" wide wheel (above left). In a rush to get these onto our car during the 2018 NASA Championships with no prior testing, I just slapped a big spacer on each corner to make it clear inboard, and it poked (above right) outwards. Not my proudest moment.

                      According to tire markings, the "315" tire set (left) should only be 40mm total wider than the "305mm" set (right)

                      This giant 315mm Hoosier is so big it would actually be better utilized on a 12" wide wheel, but that would create even those fender poke problems, so we're sticking with 11" wide wheels for our shop car - for now. There may come a time when we cannot ignore the 335mm tires for street tire events, and we do have new front bodywork coming sometime in January that could help there. I've just decided I don't want to modify the rear fenders on our 2018 GT here, as that is impossible to "un-do".

                      After the COTA Championship event we got back and wanted to remove some or all of the wheel spacers I added there - in our last forum update I mentioned that we made some changes for the 315mm Hoosier setup. I have a few images to show the steps to gain inboard rear tire room on a S550 to do this. This is an old trick we first figured out for the S550s in 2014 but didn't photograph until now.

                      Watch the rear e-brake cable for rubbing. The 305/30/19 fit like a champ but the 315/30/19 Hoosier needed more room... That e-brake cable bracket is pretty easy to move....

                      After a little persuasion we gained over a 1/2" of rear inboard tire room, and I was able to remove the 3/8" thick spacer added on the back to clear the Hoosiers. Up front we tweaked some adjustments to the strut/spindle location, then opened up the strut tower opening, and managed to reduce the spacer needed by half... but I'm still not 100% happy with that end.

                      Again, this is a non-issue with our S550 19x11" spec'd wheels and 305/30/19 tires (below left), or even our 18x11" wheel spec and 315/30/18 Rival-S tires (below right). Just an issue when running 315mm Hoosiers - which run really big.

                      POWDER COATED ROLL BAR

                      We are still not ready to make a production run of this S550 bolt-in 4-point roll bar yet, but at least I got our prototype powder coated. So it is not raw steel anymore.

                      One of the many advantages of having a real roll bar - other than the obvious safety aspects - is it gives you a place to mount a video camera mount. The I/O Port articulated, isolated mount is bolted to the diagonal in the main hoop (below left). With the camera mounted here we can see what the driver is doing better.

                      I'm still researching modern vidcams that have the features I need: remote start/stop, remote mic input, and a proper FOV lens. My old unit would work, but its fairly old and the image quality shows. The wide angle/fixed lens Sony HDR-MV1 (above right) is still being used on a RAM mount suction cup mounted to the windshield, for the near term. And yes, that is a Toll Tag on the windshield. #BecauseStreetcar

                      OHLINS R&T INSTALL

                      We have been really happy with the Ohlins R&T shocks that we have tested and installed on number of customer cars over the years. We became a dealer for this Swedish monotube adjustable coilover company in late 2017. They wanted us to try out the S550 kit and sent us a set for testing - which we installed onto our 2018 right after COTA Nats.

                      The main difference between the Ohlins R&T kits and the MCS 1/2/3/4-way Motorsports shocks are the following: Thr R&T kits include springs and parts made so that they can work with the OEM top mounts. These kits often include remote ride height adjusters, when necessary. Its a complete kit in one box. The MCS kits don't include springs, remote adjusters, etc. The R&T kits have one knob that adjusts Rebound (mostly) and compression (a little). They are usually sprung and valved for street use with some track use. MCS kits are valved for the spring rates dealers order them for, and can be used on the street (many of our customers have dual purpose cars). MCS has separate adjusters for Rebound and Compression, depending on the model. We like to talk to customers about goals, tires, and uses before recommending one model or brand over another.

                      The R&T front strut uses a massive inverted strut, which is rigid and resists deflection under lateral loading. This S550 kit was setup with a 504#/in (90N/mm) front spring and comes with adapters for use with the OEM strut top mount. Of course we opted for the Vorshlag camber plate upgrade. We did have plans for street and track use, with both the RE-71R street tires and the Hoosier A7 race tires.

                      Out back these S550 R&T dampers use a non-inverted damper with the adjuster at the top. The kit also comes with a ride height adjuster in the stock/divorced spring location. We installed one of our spherical top mounts for this kit, of course (below right).

                      There was a slight challenge adapting this to the 2018 GT rear control arms, which we have shared with Ohlins - but it was a simple fix. All of this is covered in our S550 Ohlins R&T installation gallery.

                      We used our shortened Whiteline front endlinks and set ride heights where we had the MCS setup, about 1" lower than stock. This time I drove them on the street a bit before we went to our next track event.

                      continued below
                      Last edited by Fair!; 01-03-2019, 12:59 PM.
                      Terry Fair -
                      2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                      EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                      • #26
                        Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                        continued from above

                        NASA AT NOLA, OCTOBER 27-28TH, 2018

                        Loading up the car before this event was somewhat eventful - getting the trailer unstuck from my property was a mess. We had 4+ months of rain here in north Texas, which has turned the ground into mush in many areas. Amy and I left the shop early Friday morning for the "8 hour tow" down to New Orleans, and of course I got popped by the Popo 30 miles from the house, in a town with literally one stop sign. Great.

                        After some road closures, crazy detours, crappy roads, and just typical traffic we made it to the track 10 hours later by 6:10 pm, 10 minutes after registration/check-in closed. We got unhooked and ready for to take off as dusk arrived.

                        Event picture gallery:

                        Temps were great all weekend, with lows down to 59°F and highs in the 77°F range all weekend. The Hoosier A7 tires were used, which had about 7 heat cycles on them from COTA. The Ohlins R&T were out of the box stock, with their included springs that were a touch on the soft side for 315mm A7s. Again, this is really a coilover kit made for the street car that sees a few track events a year. Ride quality is excellent, by the way. They still worked admirably for the grip levels we were throwing at them.

                        We brought the Donkey inside the trailer with the Mustang, so we had a way to get around the LARGE paddock area here at NOLA Motorsport Park all weekend. My niece's son (my grand nephew?) had a ball riding around in this vehicle all weekend.

                        He also "helped" me fuel the car (with an empty fuel can), "check the tires", and had to sit in every tractor and race car on the premises. Thanks to those that let hm sit in their car when asked. He was on cloud 9 with this much machinery around.

                        I was there for our final NASA competition of the year, and I drove the 2018 Mustang in TT3 class. This set of tires had taken a shellacking at COTA but I had hoped they would get through this weekend and leave us one test session at MSR-Cresson soon after (see below for that).

                        This is an aero-centric track, with entry speeds into T1 as high as the fastest corners at COTA (145 mph+), and a 130 mph entry into T8, with sustained high speeds through the esses from T9 to T12. Other than the lack of elevation here, this track is closer to COTA than any other in the Texas/Louisiana/Oklahoma area, with similar average speeds.

                        Our car is still a tick under powered/over weight and definitely under-prepped for TT3, but who knows? I went here hopeful that the car would make some decent grip, I could test out the brakes (when we ran here with Optima earlier this year we had the 15" PP brakes with the wrong master cylinder), and we'd see if the Ohlins R&T setup worked with Hoosier A7 levels of grip.

                        I set the current TT3 record here back in 2013 at a 1:50.535 with a more prepared 2011 GT, but not a max prepared TT3 car. It had decent power, with a plastic front splitter and APR wing on sticker 315mm A6 tires. I also spent the Friday before testing and learning the track, dialing in the setup. I figured our 2018 GT would be 1-2 seconds slower than that more prepped car, but that might be enough to win the class this weekend.

                        Saturday - TT Race 1

                        We had 7:30 driver's meetings for TT with follow up meetings at 11:30 both days, which was nice. This "2 meetings per day" policy comes from changes implemented by NASA National office, which I agree with, as strange as that sounds.

                        We had 5 competitors signed up but only 3 that made it to the event. My two TT3 competitors all weekend were Bruce Mowry in a gutted E93 M3 with Hoosiers and Aero (above). He had run the Friday test day and he told me he had got down to a personal best of a 1:54 range in testing. There was also a 911 Carerra 4S driven by Joey Dumas - also gutted/prepped, on Hoosiers with aero. Joey's car lives here at the track, where he is a member, and he gets a lot of seat time here. Hmm, so scrub cars here - I might be outgunned.

                        Right out of the box on the TT warm up I got stuck behind a yellow Corvette, who went off in front of me at T1 in the first hot lap, and then came back on track right in front of me. Yikes!

                        Amy almost got the picture of this incident... I avoided collecting the yellow Corvette with a quick evasive maneuver but it ruined my lap and the session only yielded a 1:54.259 lap, putting me 2 tenths behind Mowry and 2 seconds behind Dumas.

                        Saturday TT session 2 put me into a 1:53.542 best, but the 911 ran a 1:51.669, so I was trailing by 1.8 seconds, but only back a tenth from 2nd. Saturday session 3 was a lot closer, with all 3 of the TT3 cars running 1:53 laps, less than 4 tenths separating us all, but I was still in 3rd.

                        I kept moving up the grid as I dropped time, yet still kept being held up on the first couple of laps each time. These A7 tires "switch on" very fast and get greasy by lap 2 or 3, yet other cars take longer to get up to speed. There were some quick TT1 and TT4 cars that were quicker at the end of the session, but rolling roadblocks early on. So I wasn't getting a clear track until lap 3 or 4, and by then the A7s were boiling and the oil temps spiking. Frustrating. This not being my home region it took a little time to get to know the local TT competitors and I was hoping that on Sunday I might be able to grid swap with some folks to get a clear lap 1 or 2.

                        I was really abusing the A7s by running them for 4 or 5 hot laps in a session, and usually by then the high oil temp issue would crop up and the car would go into limp mode, cutting off the top 2000 rpm of engine revs. Some of my best laps Saturday were while running in limp mode.

                        Session 4 was better - I had parked at the very BACK of the grid, planning to hold back a LOT on the out lap and try to get ONE lap clear of traffic early on in the session. I sat back there until a few guys came and asked what was up, then they moved me to like the front of the grid, and WHAMO! I was able to get a quick first lap, dropped 1.3 seconds, and jumped into 2nd in class with a 1:52.190 best. I was back 5 tenths for the day (final Saturday TT3 results shown above), but 5 tenths is not much - maybe I can find that on Sunday, getting clear track in an early session?

                        Sunday - TT Race 2

                        Now that I was dialed in a little better to this setup and track, I planned on getting my best lap in the first session Sunday. The temperatures almost always worked out to be more favorable on the first session, and this day was no different.

                        I gridded better and built a bit of a gap, so I had not only a clear first lap but a clear second lap as well. Bruce as behind me but I was enough ahead that I didn't impede him, and popped off a 1:52.177 lap 1, which was only 2 hundredths quicker than my Saturday best. I kept going and slowed down to a 1:52.544 on lap 2, but still kept at it for a hot lap 3. The rear tires were sliding like mad and I knew I had overheated the rears. Oil temps had spiked and the tires were toast. I pulled off line after Start/Finish, backed off and let Bruce go by me. That sneaky M3 driver had put some A7s on without me noticing, ran his personal best of a 1:51.873, and he jumped ahead of me! Dumas put down his best in this session at a 1:51.760 staying in 1st once again.

                        And that's how the day ended, with no TT3 competitor going quicker in later sessions. I came in after that first session and noticed a patch of cords on peeking out of the left front tire, so I was done for the day.

                        The video shows a couple of laps in this first Sunday TT session, where I almost exactly matched my time from Saturday. Losing sucks, and a 3 tenth spread from 1st to 3rd made it harder. I had seen a 1:51.5 predicted time, so the car had more in it, I jut couldn't find it. My stupid mistake of gentle out laps hurt the braking performance on lap 1, which I didn't figure out until it was too late. With cords on the LF tire there was not a good way to find that time in a later session.

                        So the $2000 set of Hoosier A7s were done in less than 2 weekends. Fudge. It has a lot to do with the weight of this car (3900 with driver and fuel), maybe little to do with the power potential of this engine, some of it is my driving style, but mostly the fact that this 315mm tire is still relatively narrow for the massive weight of this car. I didn't help things by taking more than my normal 1-2 hot laps on most of the 12 heat cycles I put into these A7s, which hurts their lifespan.

                        The weekend ran well, and NOLA region does a great job even when it is a merged event with Texas region, which triples their attendance. Sure there were a number of delays, and we ran about 1 hour behind schedule all weekend. But its the Big Easy, and you just roll with it. The suspension and spacer changes we made since COTA helped - the tires were tucked under the fenders and no longer rubbing, the suspension wasn't bottoming, and the brakes worked very well (once I put a little heat into the pads). I have since learned to not let the brakes stay ice cold for my first hot lap, so my out lap procedure now puts a little heat into the PB13 front pads, and they work perfectly on the first lap now.

                        I ran that dismal 1:56.867 best lap here with Optima back in April, with the brake hydraulic mismatch issue, on 200TW street tires. Finding 5.7 seconds from that event to now was partially from the differences in tires, but the massive improvement in braking was most of it.

                        All of the fast cars in TT1/2/3/4 were gutted race cars with full aero, but here we were in a street car with full interior, a stock engine, and out of the box R&T coilovers. Maybe losing by 3 tenths on Sunday shouldn't sting, but it still did. It was beyond time to address this oil temp issue, and I needed to think about cutting this car (to add more tire) and putting on some real aero, or the performance is always going to suffer in TT3.

                        MISHIMOTO OIL COOLER

                        If you have been following this build thread you know we have posted many times about "high oil temps" on this 2018 model. Other 2018-19 GT track rats have seen the same thing. After 1-3 laps of HARD track driving the oil temp gauge (a digital "analog sweep" readout, but with no numbers associated to it!) spikes into the red, then the computer implements a limp mode that chops off revs to 6000 rpm max, and if you keep pushing it, it drops to 5000 rpm. By that point I just give up and come in to let everything cool down.

                        What's going on here? Why is this effecting 2018-19 models and not 2015-17 GTs? We have some theories. Contrary to popular belief, we don't just service Mustangs, and not all of our customers are 100$ track rats - so we have only worked on a handful of 2018+ Mustang models. Our car is what we have the most first hand track experience and this oil temp issue with, but others have mentioned similar issues on these cars online.

                        Question: Don't these cars have a factory oil cooler? Answer: Yes they do - see above right. This little heat exchanger "brick" has radiator coolant that passes through it to both PRE-HEAT and hopefully "cool down" the engine oil once it has reach operating temperature. The radiator on the base model GTs are also much smaller than the PP or Shelby cars, as shown above left) and we think that the pre-heating (for engine efficiency / fuel mileage) works a little too well.

                        The 2018 GT also got this electronically controlled grill louver system - which can BLOCK OFF ANY AND ALL AIRFLOW to the radiator. This was originally designed for the 2015 Ecoboost cars but Ford put it on the non-PP 2018 GTs as well (see this article). "active grille shutters (on all Mustangs not equipped with the optional Performance Pack) to reduce drag at higher speeds" That isn't helping things if it is programmed a little aggressively.

                        We knew that Mishimoto made a complete oil cooler kit for the 2015-17 GT but were told that it needed some changes to fit the 2018-19 cars. We aren't going to go into every detail on this oil cooler install, as I'm waiting for Mishimoto to produce the 2018-19 GT kit. Just the highlights.

                        continued below
                        Terry Fair -
                        2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                        EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                        • #27
                          Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                          continued from above

                          The front bumper cover has to come off, as do the coolant lines and main radiator hose shown above. Then an oil filter sandwich plate goes in place of the little cooling brick shown before.

                          This oil filter sandwich plate is a very well made part and has a thermostatic bypass, so cold oil doesn't pass through the Mishimoto heat exchanger. It also has two 1/8" NPT plugs - one of which we installed with an oil temp sensor (more on that later). The "Active grill shutter" system is in the way of where the heat exchanger goes, so it was removed.

                          The sandwich plate plate is installed at the oil filter location (after removing the Ford brick) and the included -10 AN braided lines go from there to the external cooler. The oil filter then goes back below the plate, in the same spot as the OEM.

                          The heat exchanger is nicely sized and fits right behind the factory upper grill opening, with a well made bracket that attaches to the carbon composite radiator support structure above. The lines connect to the single pass cooler at opposite ends, as shown.

                          The install is pretty straight forward, other than clocking the sandwich plate and routing the lines. It gets a little tight around the giant Whiteline swaybar, but there's a 1/2" of room to the hose ends. We only added a little bracket with a Vibrant dual hose separator attached to keep the braided lines from sawing into any nearby plastics, but that might be overkill.

                          Brad and Evan wrapped up the oil cooler install and we moved on to the new temp gauges...

                          OIL TEMP / TRANS TEMP / DIFF TEMP GAUGES

                          Rumor has it that the factory "oil temp" gauge readings are fake - they are inferred numbers based on other inputs and readings. I also wanted "real gauges" that I could see without having to scroll through menus while on track. Ideally these could be data logged, but with a rear mounted camera (and me calling out temps while driving to the mic) I could capture this data with discrete, analog type gauges.

                          I purchased these three 2-1/6" "GlowShift" gauges above, which are ranged and marked for engine Oil temp (100-300F), Trans fluid temp (80-260F) and Diff fluid temp (100-250F) uses. Electric steeper gauges, work pretty well. These are all three trouble spots on the S550 chassis, especially trans and diff (and for 2018-19, oil temp). It would have been better to install real gauges for engine oil temp sooner, but our testing and work schedule doesn't always allow for this. Instead we planned to install oil temp, diff temp, and trans temp gauges during the Mishimoto oil cooler install (since the sandwich plate had the oil temp sensor port).

                          We popped the front dash cover off then the center top panel of the dash was removed. We plan to mount a 2012-13 Boss 302 Ford Racing triple gauge pod to this panel, which can be replaced if we ever want to un-do all of these mods.

                          There were many aftermarket gauge pods to choose from out there but none of them looks half as good as this Ford Racing unit, made for mounting three 2-1/16" gauges.

                          Once the gauge pod was mounted to the upper dash panel the GlowShift electric stepper motor 270 sweep gauges were installed and wired in. I'm not going to bore you with the steps for wiring but it takes a number of hours to do this correctly - where it is tired into the light circuit, with fuses, and soldering and heat shrinking everything. Brad also added weatherpack connectors near each sensor, so that things like the trans and diff could be removed by just unplugging the sensor circuit.

                          The MT82-D4 six speed manual trans was easy tap get a sensor into. We researched, ordered, then replaced the M16 threaded lower drain plug on the bottom with this special adapter we found, which has a 1/8" NPT female opening in the middle. This meant we needed to do a trans fluid change, the 2nd in 1800 miles of use, but its never a bad idea.

                          The diff sensor install was a bit last minute, and I did this one myself. I had ordered what I thought was the right adapter, in stainless steel, with overnight shipping. But what showed up five days later (!?) was wrong. Some evening searching in the Home Depot plumbing aisle got me what I needed: a 1/2" MIP to 1/8" FIP adapter. This replaced the stock 1/6" NPT lower drain plug.

                          One thing I noted when adding this sensor: when I drained out the diff (which we had changed early on to MOTUL synthetics) it was about 1/3rd of the fluid missing... gone. It has been boiling off due to high temps, we suspect. And there was a LOT of material on the magnetic drain plug. This was likely material from the clutch packs on this base model car's clutch style differential (its worn smooth out). The Performance Pack and Shelby cars all get a Torsen.

                          These gauges really do work great, especially considering they are under $70 each. The install was a total pain but in the long run it should be worth it. I am making sure I take a picture of the gauges right after I come in (it takes several minutes for them to cool down from their peak numbers) from each session, hopefully getting the AiM Solo readout to know which session (lap times) they correspond to. Again, once I get the rear mounted vidcam in place this shouldn't be necessary. Already seen some great data from these 3 gauges.

                          MSR-C TRACK TEST, NOVEMBER 24th, 2018

                          This was a member day at MSR Cresson where they were running the 1.7 CCW and a bunch of buddies were going. I had finished the gauge install the night before and was going to load up onto a trailer in the morning. Due to some things out of control, my enclosed trailer and the open trailer I normally use as back-up were both out of commission.

                          I borrowed a trailer the night before, picking it up late and in the dark. In the light of morning we noticed it was about 4" too narrow to clear the track width of this car - it would be inside the trailer fenders. So we went to a nearby trailer rental place and rented their so-called "car hauler", which took a lot of ramps and wood to get the car up onto the deck (of this tractor/utility trailer). The fenders were so tall I had to crawl out the open window. Good thing we didn't buy a Camaro - that would be impossible!

                          We made it to MSR rather later than we had planned, but the weather was overcast and cool so the "early session" wasn't the only fast session. The weather was so nice in fact that the track was rather crowded with members, and that turned into a challenge for getting clan laps.

                          Picture and video gallery:

                          continued below
                          Last edited by Fair!; 12-29-2018, 06:46 PM.
                          Terry Fair -
                          2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                          EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                          • #28
                            Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                            continued from above

                            My testing goals for this day were 3 fold: 1) Test out the new Ohlins R&T coilovers at MSR-C on their 1.7 mile CCW course. 2) Test both the Hoosier A7 and RE-71R street tires, back-to-back. 3) Get some data with oil/trans/diff temps with the newly added Mishimoto oil cooler.

                            Both sets of tires were pretty "tired" but the data was still valuable, and it would be back-to-back on the same day. I haven't done a street tire vs R-compound tire test like this in a LONG time. The first session would be on the RE-71R 200TW tires, which had 8 weekends of abuse on them now.

                            Remember, one of the Hoosier A7 tires was already showing a stripe of cord on the outside edge, so this is far from a perfect test. I moved that wheel to the left front, which is the less stressed front tire on this track. Hoping I get a clear lap in the first or second hot lap, so that the tires don't overheat and "fall off".

                            That's not how it worked out, of course. There were some rolling trains of cars, plus I got stuck behind a few slow pokes, but that's what happens on a nice member Saturday in late November.

                            I had several buddies out there, including Brian in his GT350, Jerry's last drive in his C6 Z06 (he just got a C7 Z06), and Kevin had his new C7 ZR1 on Michelin slicks.

                            As you will see in the video below, some knucklehead pulled right out of the pit lane onto the track, right in front of me on my first flying hot lap. That was the best shot at a good lap time on these tires. Gone. I also got blocked again on laps 2, 3, 5 and 6 (two of those shown above), and had a hair raising 3 wide pass on Lap 3 (the 86 driver talked to me after - he knew I was passing but the NSX pulled over on him!) I had to stick with hot lap 4, my only lap clear of traffic. Lap 4 on an A7 is usually not at all what you look for...

                            Lap times on Hoosier A7s (not showing the out lap or cool down laps)
                            Lap 1: 1:24.921 (traffic)
                            Lap 2: 1:29.021 (traffic)
                            Lap 3: 1:22.441 (traffic)
                            Lap 4: 1:21.138
                            Lap 5: 1:21.507 (traffic)
                            Lap 6: 1:22.308 (traffic)

                            The AiM Solo was showing predictive times as quick as a 1:20.5, but all I ended up with only a 1:21.138. That's still a solid 8 tenths faster than this car has ever run here on RE-71R tires, and fully 3 laps past when these tires have their best performance (lap 1).

                            After 8 total laps in this session, both front tires were now showing cords. The worst one was showing cords on the inside and outside shoulders. This tire had been flipped inside out between the COTA and NOLA weekends - the majority of the wear is from the outside shoulder, even with -4° of front camber. The tread layer was actually peeling smooth off on the outer two inches, so these tires were officially D-U-N!

                            The temps on the fluids looks within spec (pic above shot right as I came into paddock), but only just in spec for the trans and diff. We have some ideas on how to combat high diff temps that we will address very soon. Engine oil looks perfect, and I rattle off all of the temps at the end of the Hoosier test video.

                            Not having our enclosed trailer meant I had to throw a bunch of tools and such in the back of the pickup. Brought a new battery jump box / air compressor to set pressures (#500psi) and a crappy jack that will never go to the track with us again. Pulled the four wheels and tires off and took them to Doghouse Performance for a tire swap to the RE-71R streets. That took about an hour while we sat out a session and let everything cool down.

                            Made it back out in the last session of the day, 4:30 pm, but luckily the temps were still cool and the partial clouds were keeping the track from cooking on this 70°F day. It was less crowded out there, but this set of tires had been sitting in the shop for a couple of months and took a couple of laps to scrub them back in and get the tires up to temp.

                            I edited the video down a good bit, but in this session I got stuck behind some slow Miatas, a new NSX, and two Porsches. Somehow I managed 3 laps in a row without traffic.

                            Lap times on RE-71Rs (not showing the out lap or cool down laps)
                            Lap 1: 1:28.748 (cold tires + caught a slow Miata)
                            Lap 2: 1:23.065 (still cold tires)
                            Lap 3: 1:22.126 (nearly matched the best lap these tires have ever done - when new)
                            Lap 4: 1:22.440 (made a big mistake in big bend - almost had a 1:21.1)
                            Lap 5: 1:26.188 (passed a new NSX + caught slow Porsche)
                            Lap 6: 1:24.050 (lapped slow Miata + caught slow Porsche)

                            On lap 3 everything mostly worked, and got that 1:22.126. That is less than 2 tenths off my best lap ever on these tires, 8 months earlier. So the stories of RE-71Rs wearing out or falling off might be greatly exaggerated. We used these RE-71Rs at yet another event after this!

                            The difference in grip from A7s to RE-71Rs was painfully apparent, and there is one full second difference in lap times (see log of best laps for each tire, above) but I fear that the lap time differences don't show a fair representation of that.

                            With the laps on the A7s I was considerably restricted by traffic. There was some "potential improvement" I didn't reach on the street tires, too. On my best RE-71R lap the AiM showed a 1:21.5 predicted time, and on Lap 4 it showed a 1:21.1 pred, but I screwed up something on both laps. Either time would have a marked improvement over the 1:21.9 previous best lap on these same tires. Oh well, I'm a bit of a hack driver and can't always match what the computer says is possible (that 1:21.9 lap was matching predicative, so it was a better driven lap).

                            The small changes made since that March NASA TT event - mostly brakes - are what makes the difference. The Whiteline and Ohlins coilovers are using about the same spring rates (which both produce more roll than I like on Hoosiers - see the 3 phases of Big Bend, above), but some of that potential lap time improvement from March to December would be firmer spring rates & damping of the Ohlins setup. I still need to get a lap on the RE-71Rs here on the MCS RR2s...

                            PRODUCTION TOW HOOKS RELEASED

                            We didn't do much to the Mustang over the next week, other than getting the prototype front and rear S550 tow hooks ready for production. These were made back in the summer but the templates were lost in the move. Off comes the front and rear bumper covers.

                            Once the prototype pieces we made were removed they were reverse-engineered and a few updates were made. These changes make the cut parts 1-piece, to remove some welding, but we did add a cut line for the bend.

                            Getting these into CAD then cutting them on our CNC plasma table a few minutes later was nice. I love this machine and we keep coming up with new products to make on it. Getting the settings right for each material isn't easy, but we're working our way through steel, aluminum, and stainless in various thicknesses and finding out what works.

                            We now have a production batch of red powder coated steel tow hooks that bolt on without cutting any painted parts or removing critical crash structures of your S550 chassis.

                            The S550 rear tow hook kit is a 100% no cut/bolt-on part. The front (2018-19 GT) kit requires a notch be cut into the lower black grill plastics. We include a cutting template for the front 2018-19 GT tow hook kit and will be making these for the 2015-17 cars and Shelby GT350 models soon.

                            PRODUCTION S550 BRAKE BACKING PLATES

                            While we had the car apart we went ahead and made a major revision and production batch of S550 front brake cooling backing plates and 2018-19 GT brake cooling inlet ducts.

                            On the backing plate we changed from the prototype's round 4" opening to this 4" oval, as this shape puts all of the airflow "inside" the rotor ring. Pumping cool air in this region first cools the front wheel hub, then the air is pumped through the vented rotor ring.

                            This "ghosted" picture shows the backing plate's 4" oval opening being under the rotor ring of the 2015-19 Performance Pack 15" rotors. This backing plate works on the 6 piston Brembo PP brakes as well as the 380mm 6 piston Powerbrake front kit (PB caliper shown).

                            This backing plate also serves as a heat shield, protecting three different ball joints (see above right) on the front suspension from the heat radiated by the brake rotors. This is why we use 304 Stainless Steel vs Aluminum or Carbon steel - SS has better thermal resistance, and is often used for heat shields.

                            To get air to the rotor backing plates it needs to come from somewhere. On the 2018-19 GT there isn't a great place to steal air from, so we took some dead flat space in the corners of these lower grill pockets, that were likely added for styling.

                            We include a cutting template to cut a 4" oval hole and 3 mounting holes, then the inlet ducts bolt in and mount on the back side of this plastic grill. Some 4" hose connects the inlet to the backing plates, and now you have brake cooling. We are already working on some other S550 Mustang model variants and will show that next time.

                            continued below
                            Last edited by Fair!; 01-02-2019, 09:03 AM.
                            Terry Fair -
                            2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                            EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                            • #29
                              Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                              continued from above

                              SCCA CLUB TRIALS, MSR 1.3, DECEMBER 1, 2018

                              This was our last opportunity to compete on track for 2018. The Hoosiers were TOAST but the RE-71Rs had a little tread left. Send it! The weather for the Saturday event was forecast to be excellent, so right after wrapping up the new brake backing plates and production tow hooks on the Mustang I washed then we loaded up the Mustang the night before. Of course it rained overnight, and being on an open trailer, the freshly washed Mustang had spots on it all damn day at the track (see below).

                              I'd rather have a dirty car running on a dry day, of course. You can see the shape of the Mishimoto oil cooler almost perfectly fits inside the reduced opening of the upper grill in that close up pic. The back-up open trailer was back so we loaded up after I washed the car Friday for the event on Saturday.

                              We were back at MSR but running on the smaller, more technical 1.3 mile course, which has a lot of elevation change. This course is located next to the MSR 1.7 course, which an HPDE group was running that same day. The SCCA used the newly built MSR "Museum" clubhouse for the driver's meeting, and that's where most of us spent time between sessions. After seeing the insulating foam in here, I sure was glad we painted the foam insulation in our shop (otherwise it turns this yellow color in a short time).

                              At this point the 9 month old RE-71Rs weren't going to shine, but I wanted to get more temp data on the oil/trans/diff fluids as well as the Mishimoto oil cooler. Also wanted to see how the Ohlins R&T coilovers stacked up against the tough "CAM-C" class Mustangs and Camaros that run a lot of TT events in this region. I'd be learning a new track so it would be dependent on "that driving stuff" more than normal.

                              For the past 5 years the Texas Region SCCA has been holding TT events (9 events in 201 using modified autocross classes, unlike the SCCA National TT classes. While it is far from perfect, it is a lot more sensible than 2018 National TT classing, which I'm not a huge fan of. It also makes it easy for local autocrossers to "class" their cars.

                              The cars we would be running against in the combined "CAM" classes are all on 200 TW tires and include 5th and 6th gen Camaros (including many 1LEs and even a new ZL1 1LE), S197 and S550 Mustangs, and a healthy chunk of C6 and C7 Corvette Grand Sports and Z06s, including some heavily modded ones. They have a "handicap" system that merges the Pony Car Mustangs/Camaros in the same class as Corvettes. This doesn't work that well, but "it is what it is" and most of the competitors ignore the "handicap" times and just look at the raw times. This Region has some TT classing changes for 2019 that might work better. We would be looking more closely at the CAM-C pony cars.

                              Event Photo Gallery:

                              The Texas region runs their events with at least 4 different run groups on their stand-alone TT events. The group splits are based on class, experience and speed. They stuck me in the faster "Red" group, which had all of the CAM cars, instructors, and advanced folks. Passing is only with a point-by, which can only happen in two spots on this short course. With these smaller run groups, though, it worked fairly well.

                              I most recently ran this MSR 1.3 course back in August in Amy's FR-S (that car on 315 Rival-S tires could only muster a 1:10 lap). Before that event it was fully ten years since I ran the 1.3, and it was in an EVO X. So it took me a few sessions to re-learn this track and to make this big pony car dance around this tight circuit. I started off in the hunt (see session 2 results above) sitting in second only to a heavily modified CAM-S Corvette (which HPR built the 660 whp 468" LS engine for) and ahead of the CAM-C cars.

                              This was a somewhat blustery day, with ambient temps in the low 70s but high winds all day. Amy was there shooting pics and the Mustang ran great all day - running all five sessions without a hitch. The car could run the whole 15 minute session but I usually found my best laps in the first 5 to 7 laps. I kept getting quicker in each of the 5 sessions, even as the track warmed up - an obvious sign that I was still learning this course.

                              At one point I had fallen to 3rd in class, fighting with some light traffic in each of the earlier 4 sessions. By the 5th session they put me at the front of the grid so I could set the pace on the out lap. In the video above you can see that I had 4 traffic-free laps and found my quickest time on lap 3. Predictive timing kept flashing up 1:04.9 laps but I only managed a 1:05.448, which was a little disappointing.

                              Final results sorted by time for the 46 entrants in Time Trials

                              It was good enough for 2nd place in the 11 car "combined" CAM class, and quickest of all of the CAM-C Camaros and Mustangs. Barely. Scott's similarly modded, white 2016 GT on 315 Rival-S tires was only 2 hundredths back. Overall I scored 3rd quickest out of 46 total T cars - behind two C6 Z06 Corvettes. There aren't many folks running in this TT in this region on R-compounds.

                              200TW TIRES AFTER 9 WEEKENDS

                              These pics above are a good reference - this is what the RE-71R tires look like after 9 weekends and 9 months of track use (zero street use). The rears are pretty hammered, but they actually spent much of their life up front. The tires have been flipped and rotated more than once. The "fronts" still have plenty of life left in them, and if you look at the data logged in the video, they still sustain 1.25g lateral and touch 1.4g loads in spikes. Have they really fallen off that much? It would be nice to test an old set vs a new set back-to-back - only takes money!


                              This press release was sent out on Dec 21st about an experimental series of sub-classes for NASA Texas Time Trial built around a 200TW tire. For 2019 this is a Texas Region only championship that they agreed to let us try, where Vorshlag is going to provide trophies for the Street Tire competitors.

                              Press Release:

                              A little back story: NASA has the largest Time Trial series running in the United States, and they regularly bring in the largest, most competitive fields at dozens of events every year. NASA's "science based" ST/TT classing - where power, weight, tire widths, and aero devices have hard limits and are routinely measured - are attractive to the top level TT racers. Easy to understand, easy to build around, and easy to verify. We have written a post analyzing the 2019 ST/TT rules in detail, linked below.

                              More on NASA ST/TT classing:

                              Back at the beginning of NASA TT, some competitors could win classes and even set class track records on street tires (we did a few times), but that quickly changed. It wasn't long before more top level NASA TT entries moved to a dedicated R-compound and non-DOT slicks.

                              This EVO X and this BMW both took wins and/or set TT records on street tires back in 2006-2008

                              These "tire wars" have escalated, and unless you can afford to buy or win new contingency tires every time out, you have to budget $300-1000+ per weekend to stay on sticky R-compound tires. Tire costs have quickly become largest part of most Time Trial competitors' budgets. Some people have seen this tire battle play out and have opted to switch to longer wearing street tires - often with other series.

                              By 2013 we were bringing new "sticker" sets of Hoosier A6 tires, to help knock down track records

                              Since those days, the number of tire options in the 200 treadwear segment of tires has grown tremendously - tires which last a lot longer than sticky R-compounds. This growth has been fueled by endurance racing groups, autocross classes, drifters, and other Time Attack groups building classes and entire series around these longer wearing street compound tires. We have been hearing from a lot of folks about tire costs, and were working on a way to bring 200TW to NASA TT. We worked with Will Faules of NASA Texas to create this experimental series of regional classes built around a 200TW limit.

                              Optima / USCA was one of the groups that built their whole series around 200TW tires - and it works

                              In the new NASA Texas 200TW Championship, cars will compete in the existing TT1 to TT6 classes, but will also be scored during the event as a ‘race within a race’ for cars entered on and declaring the use of 200 UTQG rated tire. For example; a driver will still compete in TT1-6 but will declare in the morning meeting to be running on a 200TW tire. Tires will be verified by the NASA Texas Time Trial Director. It will then be noted on each results page during the day which cars are running in the 200TW sub-class. Regional season points will be awarded for these Street Tire sub-classes. Vorshlag will be presenting trophies for the podiums of these classes for every event as well as the 2019 Street Tire Season Championship.

                              This set of experimental 200TW classes should bring in new competitors and give existing TT folks a new option to compete on tires that could save them thousands of dollars per year. We are excited to see the outcome in 2019! If you are in or near Texas we welcome you to reach out and try to be a part of this. You will still need to earn a NASA Time Trial license, of course.

                              WHAT'S NEXT?

                              There are even more updates to show but this update is running very long. I am gong to wrap it up now with a few teaser shots if what is in store for 2019 on our car, as well as associated S550 product development.

                              The lone prototype "Auburn Pro" limited slip differential unit built for the Super 8.8" is in our hands. We are building up an all new aluminum Super 8.8" housing to use with this diff as well as 4.30:1 gears. I will show more of this next time, weights of the housings, and reasoning behind 4.30 gearing.

                              This set of ARH 1-7/8" long tubes with a catted 3" X-pipe is here and already installed on our car, but we are waiting on a CAI kit that was on backorder to arrive. When we get the car dyno tuned we are seeing how much this Gen III Coyote can make on 93 octane. Should do a bit more once it has both a free flowing inlet and exhaust.

                              Until next time,
                              Terry Fair -
                              2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
                              EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev


                              • #30
                                Re: Vorshlag 2018 Mustang GT + S550 Development Thread

                                I have been following your 2018 S550 build as I have the same base setup and am/will be modifying my daily driver/track HPDE setup. First, your posts have been a wealth of great info and inspiration and I am currently implementing the brake conversion setup (booster + master cyl + the 15" rotors + PP brembo's). I have a question which may seem 'noob-ish' but here goes...During track days I have been disabling the Traction Control + Advanced Trac (per the Manufacturers recommendation) but what about the ABS? I've heard talk of disabling it via the fuse, or just leave it alone. Could you give me a recommendation? For this or all the 'traction systems'.