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Vorshlag 2011 Mustang GT + S197 Development Thread

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  • Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build

    Terry, I forgot to ask; what have you seen in regards to tread life on those NT-01's, vs the BFG Rivals?

    I tend to run with clubs that give us 6 or 7 20-25 minute track sessions in a day, and autocross with a club that holds test and tunes with 60+ runs in a day... I need a tire that will last too!

    Comment


    • Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build

      I am curious about the battery cut-off switch system you have been using:





      I really like the idea of the solid state switch, but compared to other solid state switches, it seems like this one doesn't have a 4th pole to cutoff the alternator/ignition. Which most people say i necessary to avoid burning the alternator diodes when turning the switch off.

      Can you shed some lights about the wiring ? Looks like you simply cut off the positive pole and that's it. Am I right ?

      Comment


      • Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build

        Vorshlag, I'm glad to see the S197 work continuing!

        I have your D-force wheels 18x10. Everyone is telling me I need to run 285/35. Is that the largest tire you recommend for this wheel? Do the 295's bulge bad? That 285/35 is pretty short for Michigan roads.

        Comment


        • Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build

          Originally posted by twistedneck View Post
          Vorshlag, I'm glad to see the S197 work continuing!

          I have your D-force wheels 18x10. Everyone is telling me I need to run 285/35. Is that the largest tire you recommend for this wheel? Do the 295's bulge bad? That 285/35 is pretty short for Michigan roads.

          Guys, in case Mr. Fair does not get the time to answer this soon I did get a response back from Jason, very informative and I decided to stick with the 285/38/18 over the 295/35/18. Damn it! why can't they make a 238/35/18!

          "Jeff, we've run the 295/35-18 on the 10" wheels. While they don't get the sidewall support the 275 and 285 see, they work fine, particularly for daily driver use. We had our 2013 GT on them and were very happy with the fit."

          See photos starting here:
          https://vorshlag.smugmug.com/Project...tang/i-m2BvTtq

          Comment


          • Re: Vorshlag 2011 Mustang GT 5.0 - auto-x/track build

            Wow, long time to check the posts in this thread. I'm about to "revive" this thread so I will address some of the lingering questions here.

            Originally posted by philooo View Post
            I am curious about the battery cut-off switch system you have been using:



            I really like the idea of the solid state switch, but compared to other solid state switches, it seems like this one doesn't have a 4th pole to cutoff the alternator/ignition. Which most people say i necessary to avoid burning the alternator diodes when turning the switch off.

            Can you shed some lights about the wiring ? Looks like you simply cut off the positive pole and that's it. Am I right ?
            Good point - and we have since changed this setup on Jamie's S197. This old solid state kill shown above from 2013 was not reliable and had a failure.



            We replaced this in ~2015 with the solution above, which is a remote triggered, solenoid style kill switch. This electro-mechanical solution is more common from 1990s-2000s. Since then we have found another solid state solution...


            http://www.vorshlag.com/forums/showthread.php?t=8498

            This solid state electronic battery isolator form CARTEK linked above addresses the battery, ignition and the alternator. These ARE reliable, meet FIA specs, and have been used in Europe for years with success. We stock and sell these now.

            Thanks,
            Last edited by Fair!; 02-19-2018, 06:36 PM.
            Terry Fair - www.vorshlag.com
            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

            Comment


            • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

              Thread Update for April 9th, 2018: We haven't posted in this thread since we we sold our 2011 GT, which was mostly covering the progression of our shop car from stock to Time Trial record setting over the 2010-2015 seasons.


              From 2010 to 2015 we took this '11 GT from Frumpy 4x4 to Fast and Furious track beast!

              What's been going on in the past 3.5 years? Well we have been busy working on other people's S197 Mustangs, developing new solutions, and converting street cars into race cars. And I figured we'd be back in another pony car soon - sure enough, we bought a 2018 GT in late February of 2018, shown below. That build can be followed in a separate S550 chassis thread here, which is also cross-posted on a number of other popular car forums (some of the few that are left).


              Back in the Mustang game again! Our S550 builds on everything we learned in our S197 + new technology that has emerged since

              We will occasionally compare S197 to S550 chassis cars in this thread as well as the S550 thread, because these two chassis are both still "modern" and both can be made into excellent road course cars. Sure, the S550 has a more modern Independent Rear Suspension, but don't let that "make" you sell your S197 for an S550. We can still make S197s damned fast, and with a lower price point now we can easily make one run with an S550 on track, dollar-for-dollar!

              That is a reduced list of car forums this S197 Development thread is still posted on. It used to be a much longer list (7 forums that exceeded 1.2 Million total thread views), but some forums have died and others have veered away from "cars" to the point that it isn't worth posting there. Some folks don't like non-sponsors posting threads in their forums (even one so chock full of tech), so we have stopped posting it where it isn't wanted. But we still sponsor a few forums so we will cross-post new additions to this thread to this list above, as well as the answers to good questions we see elsewhere. Got a good question? Ask!



              We here at Vorshlag have learned a good many things in the past 8 years of building, refining and racing S197 Mustangs - on road course as well as autocross settings, on street tires as well as stickier rubber like Hoosiers. We still share damn near everything (except business related trade secrets), so if you are new to this thread, read the "back issues" when you have time. We will add more updates periodically as we work on more S197s and learn new tricks. If you get really bored we do this same "tech heavy" build threads for lots of cars we have owned and/or raced/developed, located here.

              GOOD OEM BRAKES VS MOTORSPORT BRAKES

              This thread has chronicled the good, the bad, and the ugly experiences we have had with the S197 Mustang chassis. Our 2011 GT had the upgraded 14" dia Brembo 4piston front brakes, the 5.0L engine, and we did lots of suspension and aero updates.



              But our main struggle for five seasons was with the OEM based brakes. We chronicled the testing, results, and challenges with the stock 14" Brembos, from our earliest autocross problems (above) to the real issues we had on track once we began to seriously compete in Time Trial in 2012. We found the limits of these brakes on many occasions, including this fateful shunt I had at Road Atlanta in 2014...



              That was not a proud moment, and both the car and my back took some damage. Luckily the car's dings were superficial and it was back on the race track 2 weeks later. But we still stuck with these 14" Brembos on our '11 GT for another two seasons of racing. Why?


              Left: We stopped rebuilding the cast aluminum Brembo 4 piston calipers and just threw them away. Right: Rear rotors would POP!

              There are meany reasons, but it came down to this: I am sometimes too cheap for my own good. Yes, it was a cost thing, and partially a pride thing. We made brake cooling kits for these brakes, and I thought it would be seen as a weakness if we gave up on the 14" Brembos. As I get older I learn to move past these self imposed road blocks. As I have learned, the hard way, there are situations where OEM brakes just can not work. It costs money to go to "real" brakes, but sometimes an up-front cost is worth it in the long run.


              We tried every brand of pad, all of the cooling tricks, to keep these Brembos alive. We kept burning them up...

              From 2012-15 seasons we went through a LOT of pads, rotors, calipers, and fluid. And I was side-lined at more events than I can count because we "ran out of brakes". The truth was that we were KILLING front rotors, KILLING front calipers, WARPING rear calipers, POPPING rear rotors, BURNING up front hubs, and just SHREDDING brake pads in this car. Even with short 1-2 lap Time Trial sessions. My brain just could not fathom the need for larger diameter, costlier rotors or Motorsports calipers.


              Everything became expendable - hubs, rotors, pads, calipers, pins, fluid, mounting bolts, brake cooling hoses - with short intervals

              GOOD SHOCKS COST MONEY, TOO

              Small sidebar, but it is relevant. 15 years ago I could not fathom spending more than $1000 on coilovers for a competition car. Who needs adjustable Monotube coilovers when we could do well on twin tubes? How can shocks make $3000 worth of difference?? Well that level of ignorance held me back in the 1990s and early 2000s, but when I finally experienced REAL dampers and noticed that both the ride quality AND race results improved, I was a believer. You'd think that I was born in Missouri - you have to SHOW ME why I should I spend my hard earned money on some new technology or upgrade before I do it. Or I have to crash and get hurt before I learn.



              We started autocrossing seriously again in 2003 (after running semi-seriously from 1987-1999) in the BMW M3 above. My friend owned the car at the time and had the best Koni-based double adjustable twin tube coilovers and high spring rates on it, with our early camber plates. We ran the best tires, wheels, and ran the car hard at private tests and both Regional and National level SCCA events. We both had lots of years of driving but we only did "OK". In early 2006 we bought our first set of monotube adjustables (before we became the AST importer) and immediately we noticed a HUGE difference, with the same tires, spring rates and alignment settings. We started WINNING in this car and this streak continued into NASA Time Trial events soon after (2006) in several monotube equipped cars.


              The switch from twin tubes to monotubes (above left) immediately woke up this car, and took it to trophies and National Championships

              This is why we share so much detail and post race coverage in our forum threads - so you can bypass years of ignorance and fumbling around with the wrong parts, switching from upgrade to upgrade, before you finally stumble onto the right solution for your car's on-track needs. We've been there, found the limits with some pieces, and figure out ways to move forward. Learn our experiences.



              BACK TO BRAKES...

              Well damn it, when I finally took a chance and tried a new Motorsports brake caliper & rotor upgrade, it was obvious to me that it was THE hot ticket within one lap. I was so pissed at myself - I'd spent decades in the dark relying on OEM based brake systems with just good pads and cooling. A huge advantage - ignored. From my lack of "trying something new".


              The 2-piece 340mm rotors were barely any larger, but the Powerbrake calipers were enormous! Yet 4.7 pounds lighter??

              These Powerbrake 2-piece bolted/billet calipers were the breakthrough. Of course we knew about Motorsport brakes, and had been looking for a manufacturer to work with to develop new kits and sell their products since about 2008. We just could never get one of the "big players" to work with us at Vorshlag. We would talk with all of them at the trade shows: Brembo, Stoptech, AP, Alcon, etc. These guys only wanted to talk to pro race teams, weren't interested in developing new applications for the cars we had in mind (Mustangs, BMWs, Corvettes, etc), or only wanted to have massive stocking dealers that moved huge quantities - after they made a MASSIVE buy-in. None of that worked with a shop our size, but we still had the need.



              And every year at the SEMA and PRI shows we sought out new companies, just kept getting nowhere. We had never heard of Powerbrake but our brake pad supplier introduced us to these South Africans at a trade show in 2015. They had already explained to them about how fast were were killing rotors/pads/calipers on our own S197 Mustang (which we had just sold). They said we probably had too little heat capacity & brake cooling for the WEIGHT and HORSEPOWER of the car. We were a prime candidate for a properly designed Motorsport brake system.

              continued below
              Terry Fair - www.vorshlag.com
              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

              Comment


              • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

                continued from above



                We said we had tried the biggest hoses, inlets, various designs of backing plates but just could not keep the calipers and fluid cool enough. But they said it was more than that - we needed better rotors, better calipers, designed for racing. Not OEM stuff with tarted up cast calipers... it was time for REAL brakes.



                It all comes down to some equations, and we were running our S197 Mustang on the wrong side of that calculation. And it kept biting us with short lived brake performance and low consumables life.



                I drive ALL of my race cars HARD AF, and the BMW I raced from 2016-17 (above) was no different. The 330 comes with upgraded front and rear rotor sizes (1.0" larger than other E46 models) but in the first few months of the 2 race seasons I ran this BMW 330, it was running at 3285 pounds on a 245mm Hoosier R7. We were often heavier than that by as much as 100 pounds, and I was back to killing rotors/pads quickly on track. Limited amount of laps before the brakes would send me the warnings that it was "time to shut it down", take cool down laps and come in. Frustrating and expensive.



                Good brake pads get costly - you can spend $250-350/axle set on a brand like Carbotech or G-LOC - and we were burning through pads using stock rotors/calipers. But as soon as we upgraded just the fronts to the Powerbrake 340mm x 34mm 2-piece rotors and their medium sized 4 piston caliper on this 330, the brakes became... GOD BRAKES. I'm not kidding, it was shocking how much better they were. Sure, I could spike 1.1g stops for a few corners on the 330 brakes with the most aggressive G-LOC pads, but these Powerbrakes could do it turn after turn, lap after lap, without fail.



                Not to mention the brake feel was TREMENDOUSLY better. It made for a firm pedal with no squish, which I later found out was from RADICALLY stiffer caliper that no longer expanded under brake pressure when above 400°F. Why is that? Well aluminum is a low melting point metal (1220°F), but even when above 400°F (easy to get to in racing) it gets a bit "flexible", and expands under high brake pressures at these elevated temps. This means that a cast aluminum caliper can spread apart by .060" or more when hot and under pressure, which translates to a long pedal and worse feel.


                The steel bolts in the PB calipers give them tremendous strength at high temperatures

                In contrast, all real "Motorsport" brake calipers are not cast aluminum - they are forged or fully CNC machined billet aluminum that gets bolted together. The bolts are made form STEEL, which has a much higher melting point (2500°F) and is MUCH more stable at 400-500°F, long past the point where aluminum starts to get a bit bendy. So when the brakes are hot they stay stiff, rigid, with no expansion or flex. .001" of expansion at peak brake pressures and high temps is common. This makes the brakes FEEL amazing, plus they don't warp and let the pads get a taper.


                Motorsport brakes come with thicker brake pads, and combined with more stable calipers and rotors they LAST longer. 2/3rds left after 2 years!

                What did this translate into? More braking performance, consistent braking lap after lap, lower lap times, and CRAZY long brake life. We were on the same set of Powerbrake pads TWO YEARS LATER. We ran this car at dozens of events, almost always with 2 drivers. The rotors last a crazy long time, too. The "cost per lap" number gets very good, and by year 2 the 340mm Powerbrake kit already paid for itself in brake pad and rotor savings. So now I want to put Motorsport brakes on ANY track heavy car. And we have...

                We have worked with Powerbrake to develop several new fitments and have put these on these chassis: E36, E46 (our 330), 86 (our FR-S), C6 Z06, S197, and SN95 chassis cars. Our S550 kit is due in a few weeks and its being built with giant 380x34mm rotors and 6 piton calipers. Most of the previous PB installs we have done were 330mm (light cars) or 350mm (Corvettes/Mustangs). But as they grow their catalog we're always testing new bits with them.


                Ferrari specific 380x34mm with 6 piston caliper looks similar to what it arriving for our S550 next month

                The costs are reasonable - because South African currency exchanges well to the USD.This removes a bit of the sting for the cost aspect. We're seeing lifespans and performance rivaling the top Motorsport brake brands (Brembo Motorsport, AP, Alcon, Stop Tech Trophy) with a significant discount. The rotors are cast in Italy and these + hats + calipers are all machined in-house at Powerbrake S.A., with very high quality levels. But just like with Monotubes, some people have to SEE and FEEL these first hand to believe its worth the cost. The first time Jon here at Vorshlag drove our 330 with the Powerbrake BBK he was shocked - and also an instant believer. I've taken people for rides who come out wide eyed.


                Left: Powerbrake 2-piece 14" S197 front rotor = 21.5 lbs. Right: S550 14" OEM front rotor = 28.4 lbs

                The difference between Motorsport brakes and the stuff the OEMs are putting on even their top performance models is still vast. The cast calipers we see on the top Mustangs all get flexy and have worse feel, wear, etc. The weights of the bigger 1-piece rotors is up there, and the weight drop we see going UP in size to a BBK can be significant.



                I wish I had a time machine to go back and tell me in 2010 to NOT push the limits of cast Brembo calipers and rotors that were too small for the use we had in mind from 2012-15 with our car. I just didn't know any better, wouldn't open my mind to the costs involved with a brake system upgrade, couldn't fathom I'd get hurt from a cooked set of brakes. Again - maybe you can learn from my mistakes.


                This test day I drove 3 cars with Powerbrakes - including Jamie's ST3 Mustang. They were so good I was pissed...

                At one track test day (above) I got to drive three cars with Motorsport level brakes back to back. My FR-S was the first car, then our E46 330 TTD car, then Jamie's S197 Mustang GT. It was pretty shocking how well all three cars stopped. I felt spoiled!



                We do sell an S197 brake upgrade kit using the 4 piston Brembo calipers, Centric 14" rotors, and a variety of G-LOC brake pads - and we will continue to sell this. Why? Because for 90% of the HPDE drivers and even some of the dedicated race car S197 Mustangs these can work well (with brake cooling), and they are a damn bit better than the 12" or 13" 2-piston front brakes on base or earlier S197s. Its when the weights are high, the power is up there, and the grip levels are ratcheted up where these start to lose effectiveness.



                We upgraded to these 14" 4 piston Brembos from the base 13" 2-piston brakes on my black 2013 GT (above) and found a big drop in lap time. We also had real brake cooling up front, good pads, and good fluid. And we only ran that car on street tires. So while it took our entire array of brake system tweaks to make them work with this 2013 GT, it did well even on our local tracks that are tough on brakes (ECR). It was well worth the cost, and worked for the tires and uses in mind for that car.


                We had 14" 4 piston brakes on our S197 (left) and S550 (right) and over-worked them on both cars

                Those of you on Hoosiers, or in heavier/more powerful S197s on wide "200" treadwear tires might still be out-driving the limits of these 14" brakes. We did that for 4 years in our S197 2011 GT, and we're doing it again in our S550 2018 GT - just with stock power and only a 305mm Bridgestone RE-71R. So we're upgrading to real brakes before I get killed.


                Vorshlag Tech Tip Video: S197 vs S550 OEM Brake Options

                The video above summarizes much of this post in a 12 minute video - with lots of side-by-side comparisons and first hand experiences. We show weights of calipers and rotors for various OEM S197 and S550 options, as well as the Powerbrake calipers and rotors. Worth your time to watch.



                I'm eagerly awaiting the 380mm 6 piston Powerbrake fronts for our S550. I'll post up again here next time when we have these in our 2018 GT. I'm expecting 2+ second lap time drops with these, like we saw in our 330, FRS and other cars we have done these brakes on. Stay tuned!

                continued below
                Terry Fair - www.vorshlag.com
                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

                Comment


                • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

                  continued from above

                  JAMIE BECK'S S197 - FROM STREET CAR TO RACE WINNER

                  We have done a lot of work to Jamie's S197 race car over the past 5 years and I wanted to continue along with the upgrades we performed in this thread. In my last post from July 2015 I showed an upgrade on Jamie Beck's S197 Mustang where we went from AST monotube single adjustables to MCS Remote Doubles.



                  This was back when he was getting more serious about his dedicated track car, which we were converting into the W2W car it is today. He was running more and more HPDE events, getting faster each month, but still running on 315mm BFG Rival-S street tires and 18x11" wheels. This tire was chosen to give him more track time per set, and they were managed like a race tire (as the Rival-S and RE-71R should be). These are a little easier to manage than a Hoosier R7 or especially A7 (he uses both now for race and quali sets).



                  This car was still running the 14" 4 piston Brembos at the time, too. We had been managing the brake caliper/fluid temps with brake cooling but it was still going through front and rear rotors and pads very quickly.



                  The car was already converted from street car to W2W full safety gear. Full gutted interior, full roll cage, seats, harnesses, fire system, race defroster, remote power cut-off. We did the bulk of this work in late 2013, and he enjoyed running the car with the safety these upgrades provided at local tracks like ECR, MSR-C, TWS, etc. He was on track 1-3 times per month, getting more familiar with these tracks, and of course more seat time.



                  UPGRADED HALO STYLE SEAT

                  When we first converted this into a race car we supplied Jamie with Cobra Sazuka seats. We had them in our car and in our showroom, and they are a great seat for an intermediate driver or dual purpose HPDE/street car. But as Jamie's lap times dropped he wanted a more secure seat.



                  The next step up from this seat is one with a head restraint built in, or a "HALO" seat. We moved up to this in our S197, even though it was a "street car" and only had a 4-point roll bar. I really liked the added safety of the Cobra Evolution seat we added - also moving up from the Suzuka seat. At the time we were selling more Cobra seats but we were transitioning over to more Sparco seats. We also use a smattering of RaceTech, Corbeau, and some OMP seats as well.


                  Cobra Evolution seat that we ran in our 2011 GT has head restraint built in with these "visibility" holes, which were handy

                  Sparco make three series of seats with HALO style headrests. We keep two of these in stock so people can "test sit" and see which fits them better. As similar as these seats look, they are very different once you sit in them.


                  The Circuit (2nd from right) and Pro-ADV (far right) are 2 of the 3 common Sparco HALO seats

                  For my torso length the Circuit seat style fits me better. For Jamie it was the PRO-ADV. The differences is in the base, with the Circuit having another 2" of height hidden in the bottom. We want to see the shoulder harnesses holes right at your shoulders - not inches above (bad) or below (worse), to get proper belt contact with your body.



                  So we upgraded Jamie to the PRO-ADV seat, which is a more serious seat for more serious race cars. His Suzuka was legal, but the HALO seats will crash better and they have more shoulder support for hard lateral turns. As he progressed up to Hoosiers it was a welcome bit of support, too.

                  WEIRD REAR PAD WEAR = CLOCKED WRONG

                  One of the many times we changed rear pads before his next event we saw the rear pads worn all kinda of crazy on Jamie's car...



                  Brad took these out and came to show me - wow! How did that happen?



                  Its actually pretty easy to do. As you compress the piston on the rear sliding caliper on the S197 Mustang it has to be turned with a tool that has two tits that fit into the slots of the piston. These must be "clocked" properly to line up with the pad, otherwise they will get into a bending moment and once they get hot they can warp like this. Somebody changed pads track side and they didn't line up the two tits. So if you ever see this (we have seen this several times since) just line up the piston.

                  DIGITAL DASH UPGRADE

                  The stock gauges in an S197 leave out a lot of data, and with a smaller diameter race steering wheel they can sometimes be blocked...



                  A Motorsports digital dash was an exotic thing just a few years ago, but it has become more mainstream - especially in cars like the late S197 that has CANBUS outputs from the engine computer.



                  These can be mounted in the stock gauge binnacle or right out on the column (more common), to give better visibility with a small steering wheel or altered driving position. This is actually more of a benefit than you might think. The bright LED warning lights and progressive color LED shift lights are very handy, too.



                  The AiM MXL we helped Jamie pick out also has an external GPS, data acquisition (acclerometers/GPS/CAN data), predictive lap timer and on-board memory - so it can display everything the CAN system outputs, you can set up warnings and alarms, the user can scroll through different screens to see more data on the fly, and of course you can see your actual & predictive lap times.



                  It took Ryan less than 3 hours to make a bracket, mount the digital dash, connect it into the CAN wiring, program the screens and alarms, and wrap up the install. Very easy compared to running discrete wires to all new sensors for individual gauges - which can eat up 8-10 hours or more. Keep that in mind when you are thinking of "adding gauges" to a modern car like this that has CAN... the factory sensor data is all there for the taking!

                  TIGER RACING HOOD

                  In this same round of mods we installed a vented Tiger Racing fiberglass hood and AeroCatch hood latches to secure the front - in place of the factory 2-step, cable release hood latch.



                  And I'll be honest - I'm not a huge fan of this particular hood. The vented openings are in weird places, too far back for proper ducted venting. But for a "bolt it on and go" hood (without the effort of adding a radiator duct box) it does a decent job of getting some heat out of the hood.

                  Jamie bypassed some potential issues in two ways. First, he picked the fiberglass instead of the carbon fiber hood. We've heard of too many CF hoods from this company cracking. The fiberglass version is cheaper, heavier, but seems to be more durable over time. Second, he bought one pre-fitted, pre-painted, and used. One of the painters I use has installed a dozen of these and says they need to be left in the sun for a week to "stabilize" (shrink) before he will do the bodywork needed to fit these to a car. This one had already been on a car for a while, had "settled" and been painted, so a huge time savings.



                  We adding the AeroCatch lathes to this one, as we have a lot more confidence in these and have used them on dozens of cars over the years. The "push lock" style latches we used on a previous S197 are a royal PITA to line up every time you close the hood, and are finicky to open. These just work.



                  Ryan takes the time to install these right. First he marks the areas with painters tape so the alignment of the centerline and proper spacing for the four latches can be marked. The pack of the package has a cut-out template that is easy to trace onto the tape. He then uses the hole saws of the exac diameter to make the two holes, then connects them with a body saw and grinds out the oval to perfect. A shop vac is handy during cutting to keep dust from going everywhere - including your eyes and lungs! Still use a respirator and protective eye wear, as shown.



                  You have to cut an even bigger opening on the inner layer of composite, to be able to access the hardware to bolt the AeroCatch latch in place.


                  Left: On Jamie's Mustang we used the exposed flange, top mount AeroCatch version. Right: On our car we used the smooth mount

                  We now always use the "exposed" upper flange version (above left) of the AeroCatch latch, not the "smooth mount" version. We used the smooth mount on my red 2011 GT (above right) and you have to be SUPER perfect on the install or there is a visible gap to the latch. The outer flange of the exposed style is also a bit stronger.



                  Adding and aligning the pins is tough, I'm not gonna lie. It takes a lot of mock-up, measurement, some alignment tricks, and some welding. Ryan uses four little raised spots from the radiator support that normally have rubber "bumpers" for the stock hood to weld in a nut that is threaded to fit the AeroCatch pins. These have to line up perfectly in height and angles in 2 axes to fit the hood latches when closed.

                  NEW WEIGHT SETUP

                  The new setup from the coilover swap and other mods listed above got the car into the 3400 pound range. The weight below is with half a tank of fuel (the lowest we can run in these cars with a stock tank) and driver.



                  The "ballast" of having a 1/2 tank of fuel you can never use became critical when the car and driver went into NASA ST3 class, which we solved with a surge tank. I will talk about this and more in a future post.

                  WHAT'S NEXT?

                  We will show more work on Jamie's ST3 build in the next installment, as well as some other S197 Mustangs we have tackled.



                  This track driven S197 got a similar Tiger racing hood (it fit the needs of this car) but instead of a rear wing we built a spoiler for this car. I will show the steps in that next time.

                  Thanks for reading!
                  Terry Fair - www.vorshlag.com
                  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

                  Comment


                  • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

                    Hmm, that silver M3 looks awfully familiar! I do believe its sitting in my garage right now.

                    Looks slightly different now tho...

                    Comment


                    • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

                      Originally posted by docwyte View Post
                      Hmm, that silver M3 looks awfully familiar! I do believe its sitting in my garage right now.

                      Looks slightly different now tho...[/IMG]
                      Oh sweet! Did you buy my 1997 M3? Man I loved that car, killed me to sell it. So happy to see it back in TTC trim!
                      Terry Fair - www.vorshlag.com
                      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

                      Comment


                      • Re: Vorshlag 2011 Mustang GT + S197 Development Thread

                        Ah! Thought that one in the pics was Schiers old '98. That's the one I bought...

                        Have to go into TT4 with it this year, not happy!

                        Comment


                        • Project update for January 29th, 2021: It has been a little while since we updated this S197 development forum thread, as we have not had an S197 "shop car" since we sold the red 2011 in 2015. We have done a lot of S197 development since then, and just brought another S197 into the shop for development earlier today (LS swap). But I'm not going to cover those other cars today - just this one.

                          RECAP OF JAMIE BECK'S 2013 MUSTANG

                          I am going to cover a car in more detail that we briefly covered in this thread before, but we skipped a LOT of the work we did to this car from 2014-2018. This update shows the development and class progression of Jamie Beck's 2013 Mustang GT in much more detail. Let's back up 3 shops ago and start where this car went from street car to gutted, safe, caged race car.



                          We worked on Jamie's Mustang a little in 2013, but in 2014 we turned this from a street driven dual purpose HPDE car (above) to a wheel to wheel race car, starting with some major work we begun at our K Avenue Plano shop.

                          2014 UPDATES



                          In July 2014 we took this car in, pulled the roll bar, fully stripped the interior, and got the starting weight (sans seats) down to 3276 pounds. This Track Pack 2013 GT car already had AST coilovers, 18x10" wheels, Whiteline Watts, and some other suspension upgrades.



                          It was the first car my then new hire Ryan caged at Vorshlag, and it was amazingly good work - still one of the nicest cages to come out of our shop. We also installed a lightweight heater/defroster, fire system, and more.



                          The Mustang was not rated for wheel to wheel racing in NASA, and the added wing made it more competitive, but Jamie spent the next 2 seasons gaining confidence, seat time, and getting some driver coaching in HPDE settings.

                          2015 UPDATES



                          In 2015 we upgraded his Cobra Suzuka seat to a Sparco ADV "halo" style seat, with the upper head restraint. We also changed out a Whiteline upper control arm with the Multimatic spherical version, with another spherical bushing added to the axle side.



                          He continued entering HPDE events, and used full safety gear, as he progressed up the ladder towards W2W racing. Seat time, coaching, etc.



                          Later in 2015, with his goals of W2W racing closing in, we upgraded the AST single adjustables to MCS Remote Double adjustable monotubes. There were some other changes to the hood (fiberglass vented design with Aerocatch latches), custom endlinks for the WL bars,



                          The stock oil pan was swapped out for a larger capacity road race pan, and the stock trans mount bushing was updated with this steel version we built.



                          The first Getrag MT82 let go, so a replacement and fresh Exedy clutch went in in late 2015.



                          2016 UPDATES

                          For the start of the 2016 season, it was time to move from 18x10" wheels and 295mm tires up to 18x11" wheels and 315mm tires - still 200TW for now, to maximize seat time costs.



                          After months of events and brakes starting to be a concern, the end of the 2016 brought an upgrade to Powerbrake 14" 6 piston front brakes, 4" brake ducting, a new brake duct inlet, and AJ Hartman dive planes.



                          The end of 2016 saw a move to Hoosiers and Jamie earned his provisional "R" license for NASA Wheel to Wheel. As you can see it initially started out in ST2 class...

                          2017 UPDATES



                          By 2017 began running in NASA Texas season, running all season in ST3 with 377 whp avg with a stock Gen I Coyote 5.0L engine, stock cats, and stock manifolds.



                          During the 2017 season we upgraded the plastic 302LS splitter to a fully 8" deep and much wider custom splitter, which we built from 3/16" aluminum. The splitter struts were mounted to the Ford Racing bumper beam he had installed previously at another shop, which already had torn the front bumper cover at the tow hook mount. I am not a fan of this bumper beam.



                          The splitter struts passing through painted part of the bumper cover wasn't my favorite thing, and we had done the same thing to my 2011 GT. Something just seemed off, but I let it go at this point. The bumper beam underneath was so narrow that there wasn't a lot of options. Ballast was run all season in ST3, bolted to a ballast rack we built in early 2017.



                          A typical wheel to wheel weekend with NASA usually involves an optional Friday practice day of 1-4 sessions, Saturday is Practice, then Quali, then Race, and another Race. Sunday is a repeat of Saturday. LOTS of time in the car, and when its hot you need some help - like this cool suit system we added in June of 2017.



                          By August of 2017, after the 2nd Getrag MT82 exploded, we installed a T56 Magnum XL (and changed rear gearing back to 3.73) and removed the stock cats, but he was still able to run ST3 with the right ballast.



                          The replacement flywheel was lighter, and with another Exedy clutch more pounds were dropped during the trans upgrade.



                          The 3.31 gears came out and a new set of 3.73 gears were installed. We also plumbed up a transmission cooler to the T56 Magnum XL, to protect that transmission investment for years ahead.



                          A Tilton pump was used and the AN hoses were routed to a cooler behind the right rear tire. A deflector was built and placed on the "tire side" to keep the cooler from getting sprayed with dirt and rocks.



                          A lot of track miles had racked up on the stock catalysts, and this was no longer street legal anyway, so to remove risks of a burned/blocked cat we replaced them with these "test pipes". We don't do this on street cars, EVER, but for this dedicated race car it made sense.



                          At the end of August 2017 this transmission and other associated work was done. The above weight is without driver, ballast, or fuel.



                          In October 2017 the Mustang was in for some additional AiM sensors (brake pedal sensor, oil temp sensor, etc), some fresh front hubs, cool suit wiring repairs, some trans pump wiring (now it runs automatically, with key on), and a new corner balance (above right) with ballast, fuel, and driver weight included. 3765 race weight with all of the ballast.



                          At the last race of the 2017 season, at NOLA, Jamie was setting a good pace. He was leading ST3 class and a back marker blocked him and they collided. Or something like that. Anyway, the Mustang fared a lot better than the other car, but still took some damage - and he finished the race. Jamie and some fellow racers did some post-race repairs, reattached one of the splitter struts that broke off at the Ford Racing bar, and finished the next race also. But not it was in the shop in November 2017 for repairs...



                          We removed the damaged bodywork and reinstalled the replacement LF fender, bumper cover, and repaired hood. We also repaired the bent frame horn on the left front. My earlier dislike of the narrow Ford Racing front bumper beam was proven true in this light accident - the LF corner took all the brunt of the impact and destroyed the headlight, bumper cover, fender, and hood. The hood was repaired (sort of) by a shop that we don't know or work with. We had some trouble fitting them, but we managed to get their repaired and replacement bodywork reinstalled.



                          To remedy the design issues with the now damaged bumper beam, we replaced it with this custom built version that was rolled and then bent to match the shape of the bumper cover. This much wider design should help protect more of the bodywork if the car is ever in another accident. It was built by one of my fab guys at the time, Aaron. Sadly he left after only half a year (got a good factory gig with really good benefits) and he was sorely missed.



                          Aaron was able to shorten and relocated the existing splitter struts (FTR) and make a much cleaner pathway for each one to mount to the new bumper beam. The stock lower grill and the foglight / brake duct openings were used for these pass-thrus, and not through the paint.



                          Proper, thin aluminum sheet radiator inlet ducts were also built to go with the replacement Mishimoto radiator. This seals up the front upper/lower grills with the radiator, as all of the stock plastics were smashed. Aaron also added this tow hook extension to the curved bumper beam, which reached down through thr lower grill opening to mount a proper tow hook.



                          The detail work Aaron did was simply amazing - the stainless mesh screen in the lower grill (to stop bugs and klag from fouling the radiator fins), the bumper beam, the splitter strut routing - it all really came out top notch.



                          The repair work for the crash damage, plus a host of other upgrades, was complete at the end of November 2017 and he was race ready again. I was so impressed with this wider, curved bumper beam design we have since added them to numerous race cars we have built.



                          JACKING RAIL REINFORCEMENTS

                          Being able to safely lift a corner or a whole side of a race car at the track, safely and quickly, is important.



                          Back in late 2016 we added this Watson Racing Jackplate kit, which is a great deal for only $75. Donnie who worked for me in 2016 did the stitch welding, and Jamie wanted this point placed on each side in the middle of the rocker seam - for a quick "one side" jacking point.



                          Well by December 2017, Jamie had realized that it would be helpful to have a jacking point closer to the front, so Aaron took some 1.25" square tubing, sliced it along the top edge, and stitched that over the rocker seam as shown.



                          With these welded in, seam sealed, primed and painted the rocker pinch weld is protect, and a notch was added to the plastic lower rocker panels to be able to access this jacking point.



                          One last update done in December 2017 was this dead pedal, which we added to the false floor already installed on Jamie's car. Aaron made a pattern, transferred to aluminum, bent it up, bolted it in place, and added grip tape to the surface. Still with plenty of room to the clutch pedal and built around the cage tubing there.

                          2018 UPDATES

                          In 2018 the ST3 field shrank, and Jamie had a lot of friends running in ST2, so he switched to this class. The power to weight ratio then changed from 10:1 in ST3 down to 8:1 in ST2 (before modifiers). This is a big jump...



                          The Mustang was back at Vorshlag briefly in February 2018, after he had another shop install long tube headers. We normally would have done that work but we were buried in work before our shop move a few months later. The peak power was up to 445 whp and 409 wtq, which is a great. Using NASA's average hp formula it showed to be 417 whp average.

                          LET'S RUN THE NUMBERS FOR ST2 (2018 Season)



                          With the new and improved average power dyno test (417 whp avg with long tube headers), using the Super Touring 1-4 class rules, the new minimum weight are easy to calculate.
                          • Super Touring 1 (ST1) = ​“Adjusted Wt/HP Ratio” equal to, or greater than,​ 6.00:1
                          • Super Touring 2 (ST2) = ​“Adjusted Wt/HP Ratio” equal to, or greater than,​ 8.00:1
                          • Super Touring 3 (ST3) = ​“Adjusted Wt/HP Ratio” equal to, or greater than, ​10.00:1
                          • Super Touring 4 (ST4) = ​“Adjusted Wt/HP Ratio” equal to, or greater than, ​12.00:1
                          The rules are pretty straight forward for ST1-ST6 classes, and the spread between the classes has been cleaned up in the last few years - its an even 2 lbs per whp jump from each class. 417 whp avg x 8.0 pounds per hp = 3336 lbs min weight. But then there are weight modifiers...



                          continued below
                          Last edited by Fair!; 02-01-2021, 03:01 PM.
                          Terry Fair - www.vorshlag.com
                          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

                          Comment


                          • Continued from above

                            Since that 3336 is above the threshold for "running lighter than 3000 lbs" penalties, so there was actually a bit more he could have gained (weight bonus) - if he could run even more power. Which with a Coyote, becomes a real issue - the "reliable" power limit is about 450 whp on a Gen I engine. This car doesn't have a sequential, dog box, non-DOT tires, or any other bonus or penalty modification. When he ran the car in ST3 at over 3800 pounds race weight (with ballast, fuel and driver) he had a +0.5 bonus (from total weight) to his 10:1 power to weight ratio (9.5:1), so he could run even more power - but not the new 417 whp average after adding headers.

                            3700 pounds / 417 whp = 8.87 pounds per whp (ie: the REAL number)

                            With the current minimum weight goal we could get the car + driver + minimal fuel load (around 3700 lbs) and the 417 whp avg his ACTUAL power-to-weight ratio was really 8.87 pounds per hp. That is solidly RIGHT BETWEEN classes ST2 and ST3. I ran into the same problem in my 2018 Mustang when running in TT3 and TT2 for 2 seasons (which use the exact same rules as the ST classes) - as soon as we upped the power level, the power and weight calculation always put this car in between these two classes' numbers, too. That's not a fun place to be when you are competing against cars at the bleeding edge of a class' p-to-w.



                            In both Jamie's S197 and my S550 (above) there was no way we could get to the limit of the power-to-weight of the ST2/TT2 class. The chassis don't get light enough and the Coyote engines just don't make enough power to reach that (it would need to make roughly 550 whp peak, and Coyote engines built to take that live "ones of laps" at that level). At Jamie's car's real 3700 race weight, to be at the limit in ST2 he would need to make....

                            3700 lbs / [ST2 8.0 - 0.5 "bonus" = 7.5 pounds-per-whp avg ] = 493 whp average (theoretical limit)

                            So at 417 whp avg, he would be running effectively 76 horsepower under the limit of the ST2 class. Getting DOWN to the minimum weight calculated the other way (3336 lbs) was not possible without MAGICAL means (you would have to cut away too much - there just isn't a way legally to get an S197 that light in Super Touring). He knew this, and just decided to run the car in ST2 "heavy" at 3700 pounds with driver, or 364+ pounds overweight. We did the same thing in our 2018 GT, with fairy dismal results. But he still wanted to go to ST2, so ALL of the ballast could come out (the ballast rack in the trunk) as well as unnecessary fuel ballast.



                            Everyone who has tracked an S197 hard knows this - the OEM saddle tank is notorious for fuel starving BADLY when below 1/2 tank in a left hand corner. To remedy this and add much needed ballast for ST3, we asked Jamie to run his tank nearly full before every session (which is nearly 100 pounds of fuel). Now, with a huge minimum weight drop it was time to remove the fuel ballast, and to do that we needed to remove the fuel starvation issue at lower fuel levels.



                            We didn't want to re-wire the car to use an aftermarket EFI system, so instead the stock pump was kept in the tank as a LIFT pump to then feed this Radium Engineering external surge tank, which had its own internal pump and fuel pressure regulator.



                            Aaron performed the wiring and plumbing work, and without having to re-plumb the whole car or do any EFI magic we were able to get this accumulator system added which allows the stock tank to work "down to the last drop". The extra capacity of the surge tank is always kept full, so he can finish a race with just what's in the surge tank if needed. In the end the fuel surge tank worked GREAT and it has run flawlessly for the years since we did this in 2018.

                            2018-2020 HIATUS...

                            Jamie ran most of the 2018 season in ST2, and did surprisingly well even down power / overweight for the class. But then another out of class competitor somehow missed the big Mustang bearing down on him at Hallett in the Summer event, turned into him, and there was another incident. Maybe the car should be painted hot pink and have a red flashing light on top??



                            With all of the costs of wheel to wheel racing, entry fees, travel budgets, tire budgets, and then the previous repairs from the 2017 incident, the costs got too high and Jamie put the car on ice before attempting the repairs. It sat in his trailer for more than 2 years, but in late December of 2020 he was ready for the car to come in for repairs, and his budget had recovered enough to stomach what would come next.

                            2021 UPDATES

                            "Don't hate the player, hate the game". Nobody likes paying for crash damage, and we don't like "making money" this way, but its all part of the W2W game.



                            Just getting the car out of the trailer was tough, and took nearly 2 hours. The RF wheel was busted, the control arm and spindle was badly bent, and a tire was rubbing the inner fender. It wouldn't even roll, so we dragged it out with my tractor while the front end was on skates. Getting into the shop took some work.



                            Amazingly the same splitter we built back in early 2017 survived another car to car contact, and looked like it would need almost zero repair to be fully functional again. THIS is why we don't make splitters out of carbon fiber or sign shop material - you just LOOK at those funny and they shatter and fly off. This car was DRAGGED across the asphalt on the leading edge of the splitter, onto a flat bed and then into his trailer. It's just a scratch...



                            The structural damage was more this time - it must have been a bigger hit. The front subframe was bent, a control arm was bent, RF spindle and strut housing were bent, as well as the RF fender, corner of the hood, and one headlight.



                            We took the MCS dampers off and sent the whole set in for inspection and rebuild/repairs. The new spindle and subframe were quite affordable and arrived new from Ford within 24 hours. After securing the engine from above Brad dropped the front subframe and suspension out.



                            On Dec 31st, 2020 the new subframe, old steering rack, new spindle and control arm went into the car. Good work for the last day of the year.



                            In the first week of 2021 the dampers arrived, with the RF housing replaced and the others rebuilt (it was time). Brad reinstalled the shocks out back and reinstalled the Seals-It 2-piece grommets for the pass-thrus in the trunk.



                            After the struts were installed a rough alignment got the car to roll. Then a new OMP halo seat we had in stock was installed, since the old Sparco had been reinstalled into one of Jamie's Miatas.



                            By January 6th the car was repaired enough to go to the painter - Heritage Collision who does all of our repair work - for bodywork and paint.



                            The crew at Heritage did an excellent job sourcing new Ford fender and bumper cover. They also straightened the radiator support and reworked some poor bodywork done by another shop. They painted the whole right side of the car, replaced (and matched out lightening work) the passenger door, and blocked/painted the fiberglass hood. I stopped by January 19th to take the pics above and discuss the repairs.



                            The Mustang returned to us at Vorshlag on January 25th and we got to work. The front nose needed a lot of little tweaks and mods to fit around the splitter struts, to add the dive planes, to install the brake inlet ducts, so I asked the painter to just "set it in place". We kept the old bumper cover to use as a template for many of these items and changes we needed to make.



                            While the car was at the painter's we received some replacement parts needed: the Maximum Motorsports bump steer tie rod kit that was bent was installed (above left) and the new Safekraft belts were also put in - as well as a dozen other little things.



                            We knew the bumper beam took a hit, but after the car was pulled and everything straightened on the chassis it was more apparent. The RF corner was really bent inboard and the whole beam had tilted "up" on the mounts.



                            The only things to hang off of this bumper beam were the tow hook (which was missing/destroyed) and the splitter struts, so we didn't have to be perfect within 1/16", but the whole side was off by inches. It took some drastic repairs but Zach cut the flanges flattened out and the bent section spliced, repaired, and plated for strength. This DOM tubing is mega strong, by the way, and definitely absorbed some energy in the impact that could have bent the frame or worse.



                            There was a lot of little detail work done to the bumper cover - the grills had to be repaired and remounted, the dive planes installed, the brake inlet ducts repaired / drilled / installed, and more.



                            After less than 4 days of work the bodywork was all reassembled, the bumper beam repaired, the splitter reinstalled, and the fender liners repaired and installed.



                            Brad even tackled some maintenance - the pads were checked, full nut and bolt of the car, brake fluid was flushed and bled, things along that line.



                            The nets we installed in 2014 were now out of SFI spec (5 years) so replacements for those were installed as well, to make everything up to date.



                            Instead of replacing the 4" brake duct hoses every few races Jamie listened to our advice and we installed our S197 brake cooling deflectors onto the control arms. We installed a new tow hook to replace the damaged one, too.



                            We hustled until after 5 pm on the 28th but in almost 4 weeks we had done our repairs, sent the car to paint, they did their thing, and we had it race ready once again. Jamie was super happy to get the car back after the 2.5 year hiatus and signed up for a March race and had a February coaching/test session scheduled as well.



                            LET'S RUN THE NUMBERS FOR ST3 (For 2021 Season)

                            Jamie's car ended up at almost 3500 pounds when we finished the repairs on January 28th, and here's where we need to run the numbers again. Happily this time Jamie is looking at ST3 once again, and we know the car can be more competitive there - It will take both some added ballast to get the weight up AND a re-tune of the engine to get the power down. We will run numbers both ways for him before his dyno tune that is scheduled for next week.



                            With the nearly 3500 pound weight above (low fuel, no driver), let's assume a 3750 pound minimum race weight and check ST3 and ST2 numbers at various power and ballast levels. ST3 has one different rule than ST2 - the "BTM Aero Bonus" - but Jamie's big wing, dive plane, massive splitter setup is NOT anywhere close to the Base Trim Level aero for a 2013 Mustang GT. So that can be ignored.

                            With Hoosier R7 or A7 tires (qualifying on As, race on Rs):
                            • Option 1 for ST3: 417 whp avg (current) x [ 10.0 pounds per whp - 0.5 bonus for race weight = 9.5 ] = 3962 lbs
                            • Option 2 for ST3: 395 whp avg (returned down) x 9.5 = 3750 lbs (no ballast needed)
                            • Option 3 for ST3: 406 whp avg (split the difference) x 9.5= 3857 lbs (107 pounds of ballast needed)
                            Option 1 is pretty heavy and would require 212 pounds of ballast. The weight rack could take that but the consumables (tires, pads) would wear faster than ever before. Option 2 is no additional ballast but the average power would have to be chopped back 22 whp, which is a chunk. Option 3 splits the difference on ballast (107 pounds needed) and power loss from current levels (only 11 whp reduction). If this were my car, that's the weight and power I would run. We regularly ran that heavy in TT3 (3802 min) in our 2011 Mustang back in the 2014-15 seasons, and still won every event we entered. Of course we had 335/345 tires, which helped.



                            Jamie is thinking of running with non-DOT Michelin race tires, for various reasons, and that effects the numbers considerably. I don't think the "juice is worth the squeeze" with these tires, so I wanted to show the numbers for this case also. As you can see in the chart above, the non-DOT penalty in ST3 is pretty large at -0.7. So that more than wipes out the "3750 pound" bonus of 0.5, for a net power-to-weight ratio of 10.2:1.

                            ST3 with Michelin non-DOT race tires:
                            • Option 1 for ST3: 417 whp avg (current) x [ 10.2 pounds per whp] = 4254 lbs (+504 pounds of ballast!)
                            • Option 2 for ST3: 395 whp avg (returned down) x 10.2 = 4029 lbs (+279)
                            • Option 3 for ST3: 406 whp avg (split the difference) x 10.2 = 4142 lbs (+392)
                            • Option 4 for ST3: 367 whp avg (3750 / 10.2) = 3750 pounds (no ballast)
                            None of of these are great options. The ballasted minimum weights are pretty dang high for a 315mm tire to last any meaningful amount of time. The 4th option with effectively no ballast is going to cost him 28 whp on the non-DOT tires vs the same ST3 setup on Hoosier R7s (367 vs 395 whp).

                            Let's run the ST2 numbers with non-DOTs, below. That is jumping up to 8.0:1 base ratio class, then taking the + 0.5 bonus, but then a -0.5 non-DOT penalty (this penalty is not as harsh in ST1/ST2). That leaves it at a straight 8:1 ratio, which is still too far away for the weight and power he has to start with.

                            ST2 with Michelin non-DOT race tires:
                            • Option 1 for ST2: 417 whp avg (current) x 8 pounds per whp = 3336 pounds
                            • Option 2 for ST2: 468 whp avg x 8 = 3750 pounds (no ballast)
                            So if he sticks with the Michelins he is back to running 414 pounds heavy in ST2, or looking for a magic 51 whp average gain - which just isn't possible with the Coyote engine platform - not reliably, not for a road race car, and not without several tens of thousands of dollars of spending for a very custom, short lived race engine. An LS swap with a built race engine would be easier and cheaper - but that swap it is neither cheap nor easy.



                            Earlier today we began LS swap development for the S197 chassis, but I know Jamie isn't ready for that right now. Still, if he really wants to run ST2, that's the best way to make the power goal to get to the limit of the ST2 class, without drastic weight losses.



                            That's where we are with the numbers. Jamie has the dyno session scheduled, as well as a race alignment/corner balance at Texas Track Works. I will share later what class / weight / tires Jamie decided to run, and we will support him in whatever route he chooses.

                            Thanks for reading,
                            Last edited by Fair!; 02-01-2021, 02:51 PM.
                            Terry Fair - www.vorshlag.com
                            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

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