Vorshlag C5 & C6 Corvette Development + NewBalance and Rampage

[Fair!]

continued from above



This ball valve is at the bottom of the engine bay and is drained after every Time Trial or track test. The above right image shows how much comes out after 4 track sessions (after the August SCCA TT). Just a few ounces of clean Motul oil - no water, no grit, nothing to be alarmed about.

CHASSIS TIRE RUB + TIRE SHIELD

After this round of work above - which spanned more than 3 weeks, I had our guys put the Control Tires back on. I wanted to street drive the car for a bit, and I did. These little 275s fit so well, even with 10mm spacers at all 4 corners. But when the Yokohamas went on I showed Doug where I had felt tire rub at the last TT event...



I could feel some slight tire rub on the left front in a brief street drive before loading the car into the trailer last time. I asked about this online and multiple Corvette C5 and C6 owners noted the same thing - 1) these cars aren't exactly super precise and 2) it is common for one side's front tire to rub and not the other. Most folks just let it rub through until it stopped wearing, but the coolant reservoir is right behind this spot and I didn't want to take that chance.



This spot above was worn completely through - so I asked Doug to make this aluminum patch panel to install over the hole on the Left Front (the RF corner had NO rub).



This was held in place with special expanding rivets made for composites, and with minimal rivet heads in the way of where I was sure the tire would once again rub. This was something I would be keeping an eye (and my nose) on for the first TT session the next day. This was the last bit of work on that Friday before I loaded the car into the trailer for the TT on Saturday.

SCCA TT @ MSR 1.7 CCW, AUGUST 13, 2022

Amy and I arrived at MSR Cresson at 7 am, and the event was running the same 1.7 CCW course we do ALL of our testing at. This would be my first SCCA TT event in this C6 at a track that I actually know (I have 500+ laps here over the last 20 years), unlike the last two events at ECR, where it was a new to me track. I was still struggling to learn ECR, even after hours on the sim rig.



Luckily I do not need sim rig time for the MSR 1.7, in either direction. I was hoping my familiarity at this track and SO many track tests in THIS car here (11!) might mean we would not only win T2 class (for a 3rd time in a row?) but possibly move us up in the overall rankings. If it were not for one mega race car showing up, we might have topped the results sheet...



I had hoped to take the C6 out to Cresson in the days above to do some test laps, but we simply ran out of time. All of these changes to various plumbing systems made me super nervous that something would happen on track and I'd be spilling engine oil, power steering fluid or coolant. Luckily the C6 did not leak a drop all weekend. Whew!



For the first TT session's "free-for-all" gridding, I lined up in grid early sitting in what I thought was P2. This was to keep from getting caught behind slower traffic on the out lap. But it turns out I was in the the wrong line at grid, so I went out in P10! Figures... This first TT session at 8:45 am was only 84F ambient and I didn't want to waste it, so I picked off a few cars in the first 3 laps and finally got a clear lap on lap 4, in which I ran a 1:21.0 (a new best for the car, but only just by a tenth). I took a 5th lap and it was slowing down, as these A052 tires like to do their best on lap 1.



On the very first lap I could smell and feel some tire rub, but after decades of doing this I could tell (mostly from my nose) that it wasn't "real bad" so I went ahead and finished that whole session. I came in, jacked up the car, and removed the LF tire... Sure enough the 315mm tire was rubbing on the new "shield" that Doug had built to cover up the wear noted on the fiberglass inner structure. I figured this would happen.



I added a single 1/4" spacer to that side to space the LF wheel away from the inner structure, but nothing to the right front. And it worked - didn't rub a slight bit for the rest of the day. The LF tire now has the slightest hint of poke while the RF wheel tucks nicely under the fenders. So the asymmetric spacer setup will stay for the time being.



I was worried that our typical August summer heat in Texas would derail my plans for a fast lap in later sessions, and session 2 was at 10:45 am... but luckily it was still 84F outside for that one, and I was now gridded P4 (by times). I had a feeling there was a 1:19 in the car, so I let the car in front get a full 1/4 mile ahead of me on the out lap, then threw down a blistering 1:19.8 on my first hot lap! I caught the car ahead on the 2nd lap so I blew it off and came in. Super happy with that time - a new personal best for this car here! This is what I should have run at Track Test #11 but the lime on the asphalt wrecked those chances back in July.



That lap time moved me up to P2 overall and in grid, with the only other car under 1:20 laps being Mike Dusold's tube framed, twin turbo Camaro - he was running it with the Michelin soft compound slicks and their Pikes Peak high aero package, and he was flying.



The lap above from session 2 was my quickest up to that point, and the most entertaining lap in the car in a LONG time, so that is the one I made the video for. As I noted in the beginning of the video, the Coolshirt cooler was working WELL and we used the same bag of ice all day. It was AMAZINGLY cold and I cycled it on and off until I got going on the hot lap. I also felt like "there's a second left in the car" after my first session, and I told Amy that morning that I'd keep taking laps until I ran a 1:19.



Amy got some good pics we have since used to analyze the camber and body roll, which is down from before the alignment and swaybar changes. The oil temp issues are a thing of the past with the highest oil temp seen all day of 245F. The coolant temps did climb up to 214F for a high, which is higher than before the oil cooler - but this is to be expected when you have to stack coolers - yet 214F is still fine. That 1:19 lap leap frogged our C6 ahead of the fastest cars from the previous two SCCA Time Trials, including this C7 ZR1 on AP brakes below right (who was quickest at both the June and July TT events).



I didn't think I could improve on the 1:19.8 time so I let the SCCA RE Matt Lucas take a session in the C6 for fun in an HPDE session. He had a ball and said "this was the easiest car I've driven on this track!" (it was his quickest). But after eating lunch we still hadn't loaded up the C6, and with just a few minutes before our TT group was called grid I hopped in and rushed up - and with Dusold gone I gridded P1. This would ensure I got a clear first lap without traffic, no games needed!



Even with 92F ambient temps and climbing track temps, my first lap in session 3 at 12:55 pm was faster, with a 1:19.702 - nearly a tenth quicker, even with the higher temps. My session 2 time of 1:19.800 had a pretty big driving mistake into Turn 4 (Buzzard Neck), fighting these underwhelming brakes. I swear something is forcing me to brake 100-200 feet sooner than the S550 from before, and it is costing us major time.



With the fastest time of the 3rd TT session I was confident we had secured the T2 class win of 4 cars, and it did. Even with more sessions later in the day that 1:19.702 was still 2nd fastest overall, and the fastest street car and fastest car on street tires. If you expand the data trace graph above you might notice that this even saw our highest peak lateral grip numbers (1.53g spikes, 1.3 sustained) but the same 1.17g braking we have seen since back when we ran the RS4 tires.



After that session I was thoroughly exhausted and we let the car cool off for a bit before loading up and leaving early. Other than the brakes and my driving mistakes in session 2 (and not lining up in the right grid line in session 1) I was very happy with the performance of the car. It felt good to put the car everyone said "why would you ever race that?!" out in front of everything this side of the 1200 hp Pikes Peak race car. And we still had time to find - I am not done with these brakes!

BRAKE CALIPER AND WHEEL TESTING

Having just the one set of 3-piece Jongbloed wheels for our only "race set is a bit worrisome. What if I go to a competition event and get a flat, or worse? Sure, we have the two cheap sets of FlowOne 19x10 wheels, but just the one set of 18x11/18x12s for the 315 A052 tires. I want a spare wheel and ordered a fresh set of 315/30R18 A052s the DAY they came back in stock - the set we have been running were purchased and I have been running them since 2020!



Buying another $4400 set of Jongbloeds and waiting 3-4 months to get them is not really my idea of fun, so I tagged in my account specialist at Tire Rack to peruse through their catalog looking for an 18x11" wheel with 5x4.75" PCD and the wacky backspacing we needed. I gave him a bunch of numbers and he spit out a few options, but really just one set worth using - these 18x11 O.Z. Alleggerita HLT wheels, with 2 in gold (at closeout prices!) and two in black.



Well we missed one specification to give him - the hub bore! So we will need to machine just a kiss from the inside to get them to bolt onto the C6, but the offset was dead on for what we want. Sure, its not 12" wide in the rear, but they should work fine for the backup "scrub" set of A052s, with the fresh set going onto the Jongbloeds. Look for more on this soon, when we get some time on our CNC mill to do this step.



I have been complaining about the brakes on this C6 since Day 1. The JL5 base brakes are just not adequate, and even upgrading to the Z51's J55 brakes only changes the diameter of the rotors. The circa-1984 PRB sliding calipers are still limiting this car, and I can watch them flex just when we are bleeding the brakes. The pads wear at a taper, too. So I did some looking and found some J56 (C6 Z06) fixed calipers in the 6 piston front, 4 piston rear sizes. We test fit the 6 piston front with a new smooth 14" (355mm) Z06 front rotor and it just cleared the wheels, whew! Look for more on this in the next installment - along with some real back-to-back and data logged testing.



Lastly, there was an issue with this SLP cold air kit. The plastic portion keeps popping off the silicone hose that attaches at the throttle body. So that was cleaned thoroughly and epoxied together at this joint. We will see if this stays in place and if not, we will source another cold air kit.

NEW MGW SHIFTER

With the gearing internal to this transmission and rear gear ratio we are stuck with (3.42) the C6 is often needing 2nd gear. I've fought with the 2-3 upshift so many times that I started avoiding it - didn't even attempt it at the SCCA TT event in August at MSR. I ordered a new MGW shifter a while ago but it got here right before the August TT, so we installed it the week after.



Now I'm not one to blindly buy and install aftermarket shifters on EVERY single car I drive on track, and it is more rare for me to do this. But after so much trouble with this C6, and such good feel with the same shifter on Koenig's C5 (which I have autocrossed and tracked in the last 2 years), it was time.



CORBEAU EVOLUTION X VS CORBEAU SPORTLINE RRS SEATS

It is no secret that fitting a seat into any C4/C5/C6 is a real challenge. We ran into this on my C4, on Koenig's C5, and again on this C6. This Corbeau RRS reclining seat was a huge compromise for the ability to allow Amy and I both to drive the C6, with a slider to go between our vastly different heights.



We have revised these brackets so many times I hate to think about it, but they finally slide forward and up for Amy, then down and back for me. But due to the constraints of the C6 interior and the fact that we NEED to have a rear bracket to mount the anti-sub and lap belt harnesses (see below left) it makes for an imperfect seating position for me.



It is hard to show this but I am lacking about 1" of rearward movement compared to the (terribly flat) OEM seats. To fit my head under the roof I then have to tilt the seat back a lot, so my legs are too close to the dash and my back is leaned more than I like. I barely fit in this car - its like "Miata with a hardtop" difficult for me.



Reading a UK C6 racer's blog I stumbled upon a seat that promises to be made to fit the C5 and C6 Corvette with a narrower / thinner seat back, NO TILTING, but a built in back angle that "fits most drivers". This was too good to be true so I checked with Corbeau, they said it was a better seat for the C6, so I ordered a pair and we got to work.



Comparing the Evolution X to the RRS they do in fact look very different, even if they are likely built on the same steel tubular frame. The Evo X has a lot less bulk in the back portion, and Doug was able to bolt that in with the Corbeau sliders and unique Vorshlag bottom mount brackets and harness mounts.



Well... for my body, it was worse, not better. The tilt angle was too vertical and it did not in fact slide back further. This was discouraging and a waste of time for our project, but Corbeau let us return the seat (it sat in the car for all of 10 minutes) and we only lost shipping costs both ways.



A little musical chairs and both seats were back to the RRS norm. We could put a "race" seat in this car and possibly find some room, and we have done that briefly - we talk about the seat mounting challenges of the C5/C6 Corvette in this new forum post.

WHAT'S NEXT?

Yikes, this "quick update" got really long, but we are finally caught up to real time! We have the J56 brake upgrade happening soon with new G-LOC mono-pads and some missing parts from the kit I ordered inbound. I had signed up for an SCCA autocross with this car but wee cancelled at the last minute when we saw a weird course design (which proved to be wise - it was an event plagued by delays on a very hot August day).



We will run this C6 in CAM-S (or XS-B) autocross class, and several more Time Trials in the coming weeks. I had way too much fun in Koenig's C5 (above right) over the past couple of years, and I think this C6 is closing in on the performance of that car. We also have parts inbound to finally add the "Continental" program to the Mk60 ABS, hoping for more braking force at the limit. Its either in the calipers or the programming! Amy is finally going to make some laps in this C6 again soon as well.

Thanks for reading,

[DrinkinPepsi]

Have you looked at the ST3 seat from Marrad Industries?


I have an 06 and I'm headed down this path from AutoX.

I have brake ducts, Dewitts with oil cooler, Z06 PS cooler. Koni adjustable shocks and Z51 conversion suspension and brakes, Strano Front Sway

I'm really looking at
1. seats/ harness
2. 18x11 square setup
3. MCS
Do you think that is the correct order? Is there something not on that 3 that should be there instead?

[Fair!]

Have you looked at the ST3 seat from Marrad Industries?


I have an 06 and I'm headed down this path from AutoX.

I have brake ducts, Dewitts with oil cooler, Z06 PS cooler. Koni adjustable shocks and Z51 conversion suspension and brakes, Strano Front Sway

I'm really looking at
1. seats/ harness
2. 18x11 square setup
3. MCS
Do you think that is the correct order? Is there something not on that 3 that should be there instead?

Haven't seen that seat - i will check it out. As for your modifications / order, it looks proper. I'd hustle my way down that list - the tires and coilovers are the biggest payoffs!

[Fair!]

Project Update for May 31st, 2023: I waited to long to update the build thread so I broke it up over a couple of weeks. In this post we cover build progress, TT competitions and even an autocross from August of '22 through October of '22. We also began to wind down development work, as we were quickly approaching a line where further mods would move this 2006 Corvette into "race car only" category - right now it is still a REALLY nice street car.



The 2022 competition season was very hectic and this C6 gave me and Amy a chance to get back on track and gain more experience with some new course layouts we had missed during our hiatus from Time Trial competition during the worst of the Pandemic (2020-21). I drove the C6 at 16 of the 30 events I entered last year, which are shown below in a partial screenshot of 2022 events from our "racing events" gallery (there were events in December not shown).



This C6 allow me to spend a lot of days at the track, and it was glorious, even if we were still fixing issues along the way. This Corvette was always meant to be a "temporary" track car for Amy and I, and as the season ended last year we wrapped up our track driving in the C6 - as both of our "real" track cars were finally on hand and ready - so this Corvette is going away soon. I will talk more about in the next series of forum posts.

OUR "REAL" TRACK CARS ARE HERE

This C6 was always purchased to allow us to get some seat time until our two "real" track car builds were complete. Originally we had planned to finish Amy's 2013 FRS with an LS swap, but instead we ordered her a 2023 BRZ, which arrived in late November 2022. It now has MCS remote doubles, bushings / bars/ control arms, 18x10" wheels / 275mm tires, racing seats and a lot of other mods for SCCA Time Trial T3 class (as well as Solo STR and NASA TT4), where it is faring well.



My 2015 Mustang (above right) was running in January '23 and now has an HPR built 454" LS7 dry-sumped engine, which is about to hit the track to fulfill for my competition needs for the foreseeable future. These two cars sort of book end the performance of the C6 - with the BRZ at the lighter end with 250 hp and the Mustang being the bonkers 800 hp car with full aero at the other end. And while it would be GREAT to keep the C6 as our back up track car (I lobbied hard for this, but lost that battle!), we need room at the shop. Now let's cover some of the C6 build!

C6 Z06 BIG BRAKE KIT - ACQUIRE PARTS

The struggle I went through with the brakes on this car could fill a sizable book, and I never felt like we had a great "BBK" upgrade to shoot for. The better aftermarket solutions are $4000-5000 per axle and all have some downsides (cost, noisy 2-piece rotors, wheel restrictions, loss of parking brake, etc). After spending too many hours to count looking at options, we decided on the C6 Z06 OEM brakes, with a few upgrades. These are 6 piston front / 4 piston rear and have rotors that utilize the same parking brake shoes as the base car - so we wouldn't lose the parking brake functionality like some BBKs do.



A friend I knew from college had a "complete" set of used calipers, pads and rotors and I pulled the trigger on that deal. The front calipers even had upgraded stainless steel pistons. Of course, like many "deals" turn out, one of the boxes mysteriously showed up without a rear caliper in it - so I got to buy a new one to fix that situation (at which point the cost savings got a lot worse).



The rotors were worn but not terrible, but one of the used ones had some deep grooves and was replaced with more "non-cross drilled" smooth units. Of course we ordered new R16/R12 G-LOC pads for use when these went in, a few months later. Why wait? I had more ABS testing to do first, namely the much revered "motorsport" Mk60 programming I wanted to try, before we swapped to the bigger brakes. So we kept the Z51 brakes for a a bit longer (too long, in fact).

FRESH TIRES ARE ALWAYS FASTER!

The Yokohama A052 was hard to get in 2022 - because it was the fastest tire in the widest size (315mm) for bigger cars, so back in late August '22 when a set came back in stock I jumped on it.



These weren't installed until October, as the last set was still winning events. I wanted to get through the Mk60 testing, then the BBK, then put the $2000 set of A052s on for the SCCA's Fall Time Trial events.

MACHINING OZ RACING 18X11 WHEELS TO FIT C6

I am a wheel junkie - there should be a 12 step program for people like me. Even with four sets of wheels for the C6 now, I felt like we were missing a backup set of 18x11" wheels. Honestly, this would be an ideal set to use for 315mm "scrubs" at practice events, and keep the "fresh" 315s for actual competition events. The two sets of 19x10" wheels were showing their limitations on width, and only having one set of $4400 Jongbloed 18x11/12" wheels...



Jason and I poured over wheel catalogs looking for the oddball offset that the narrow body C6 needs, and our buddy Nate at Tire Rack found some good deals on some OZ Racing 18x11" flow formed wheels - lightweight, had the wacky ET75 offset we need, and the right bolt pattern. Two were on closeout at a great price but they were gold, then I bought two more black wheels at full price - still a savings! bought this set in late July, but in August when we went to test fit them we found they had the wrong hub bore... too small.



Luckily we have CNC machines and our crew dialed these in, so in early September we had 4 new 18x11" wheels with the right offset and hub bore, but two different colors.



I planned on getting a media blast cabinet soon after, to remove the gold and black finish, then have them powder coated in the iconic Bengal Red that we had the Jongbloed wheels done in. We already have wheels and tires for many projects all over the shop so we boxed these back up and put them up stairs in storage. Then I got really busy in the Fall of 2022 and kind of forgot about these wheels - until I literally started doing this write-up in May 2023! Too much going on to keep this "temporary" track car in my brain, I guess? Now that we do have the blasting cabinet I might get these re-done and sell them.

ISSUES WITH SLP COLD AIR

The SLP Cold Air kit for the "LS3" Corvettes never fit this car well, and after many events we would notice that the plastic section that goes over the radiator would POP OFF from the silicone adapter that bridged between the 90mm throttle body and that cold air section. This isn't helping the tuning one bit!



This was finally fixed with a bead of epoxy at this joint - covering the joint shown below right. In hindsight I never should have bought this "cold air kit", as it caused more problems than it solved. A proper metal sleeve inside was likely the better answer, to give some rigidity to the plastic for the silicone hose coupling to clamp to.



While this never came apart again we ended up replacing this entire system with a carbon cold air kit from LG Motorsports in 2023.

APEX HPDE, MSR 3.1, SEPT 10, 2022

We loaded up the C6 into the trailer on September 9th with the old set of A052 tires, as this was just going to be a "practice" event for me. APEX had an HPDE event where they were running on the MSR 3.1 mile course, and I wanted to use that to get familiar with the layout for an SCCA TT we are running there in a month.



Brought my buddy Erik Koenig from HPR along with me to ride along in a session, too. I haven't run the 3.1 mile course since 2013 (where I set the TT3 track record at 2:22.7 - which still stands), so I was a VERY rusty and struggled to find lines and string together a good lap, even with some simulator time the night before. It was a big challenge to remember all 16 turns (its really about 23), plus the rough transition sections going from the 1.7 to 1.3 mile courses, too.



We got there before dawn, unloaded, and got the C6 ready. The driver's meeting was still distanced here, towards the end of the Covid Pandemic. This group has a Time Attack series in addition to their HPDE events, and we ended up sponsoring their Apex Lap Attack events for 2023.



For the first session I gridded P1 and didn't see another car until lap 4, which was great. Erik was riding shotgun with me and we took some "fun laps" in that first session, where I used the cool shirt system wearing my full driving suit, which was nice.



I was fighting with the brakes overheating and once I caught traffic after hot lap 3, we came in. The brakes felt sketchy into Turn 11, Ricochet, with the long straight before that from Turn 10. Felt like I was losing booster vacuum, so I had to use a LOT of pedal effort and brake early. I had a fairly lackluster 2:28.2 best lap on lap 4, but that was with a passenger, and we were just feeling out the track. Added some fuel (double the fuel load I ran in the 1st session) and gridded up early for session 2 to look for some real lap times.



Session 2 started out fine, leading the fast group out again, taking it easy on the out lap. But as we took the green flag and I went into the tight 1.3 section, the car suffered what felt like a massive "fuel starve" issue in the Turn 8 (Hairpin). The engine would simply LAY DOWN with zero throttle response for about 4-5 seconds after that corner, leaving me a sitting duck. Made a couple of laps like this but I was holding people up, so I let folks by and came in. Clearly this was an electronic / tuning issue, as the fuel load was too high to starve.



Spent an hour wiggling connectors, scratching my head, and texting with tuners - but could not find any issue. And this time the SLP cold air tube was finally not popping off. The fuel tank was well over half a tank, and it never did this in the 1st session. Super frustrating



Engine oil and power steering fluids looked great, with minimal fluid at the power steering cap catch rag. We ate some lunch, loaded up and left early - instead of going out and repeating the issue over and over. Weather was perfection (66F 1st session, and 75F for the 2nd).



Watching the video when writing this (after running it in later events) it is painful - almost didn't post the video. Frustrating day with not enough running 7 laps!) to learn this track well, and then this new "fuel starve" situation, and the brake heat issue was getting a bit ridiculous. If you read further you will see that we had the car a LOT faster on the 3.1 mile course in the October SCCA TT here but I had even more poor luck that held back times. anyway, this September HPDE was a bust - back to the shop!

ADDING "CSL" PROGRAMMING TO Mk60 ABS

I noted some pretty abysmal braking at the Apex 3.1 event above, and I was looking for something to blame. I wasn't ready to throw the "big" Z06 brakes at the car just yet, as I felt like there was still some room to improve with the 2005 era BMW ABS programming. And having read about "CSL" programming and worked with a few folks online, we attempt to "program" our plain jane Mk60 ABS. We had an Apex Lap Attack event coming up on the MSR 1.7 course, too!



Alas, adding the CSL programming wasted a lot of time and we eventually got it to "take", with a lot of testing, sensor programming, and even a custom config file. That last bit took some outside help - and someone from the ABS Swaps and Hacks FB page we created wrote a custom config file to make our Mk60 ABS unit take the CSL program.



We tackled the pressure and yaw sensor calibrations, which were additional steps that we were told "well of COURSE you are supposed to do that!" - it had zero effect. The CSL programming had zero effect, too - with street, track and autocross testing, as stated in the video below.



Honestly this is another case of "internet hype > reality", and after talking to a few other "less vocal" racers who have tried this on swaps they all admitted the same thing - this doesn't do squat on a swapped Mk60.



Again, the CSL programming had ZERO effect on braking g forces or stopping power. In both street ABS tests and track testing we noted the same 1.15 to 1.17g stops, before and after. In this same time period we completed some track testing on the wide body E46 M3 we built for a customer (above right), which we also performed a Mk60 swap on using the same sensors and wiring harness - and that car stopped at 1.31g. Granted, it had a lot of aero and 335/345 Hoosier A7s, but the lateral Gs were similar on both cars. I don't think the C6's A052 tires are holding it back (we tested with a new set also), as the lateral forces far surpassed what it could manage under braking. DON'T WASTE YOUR TIME




For as "easy" as this Mk60 ABS swap is supposed to be for modern GM cars, it sure is seems limited (we will have data on the CTS-V above, which we also Mk60 swapped). Every time I drive Koenig's C5 that we swapped to an S197 Mustang ABS, I regret choosing this Mk60 swap on our C6. Sure, the S197 swap is a good bit more work, but it actually WORKS better. The ABS programming scheme and technology is a decade newer and it shows. I won't make this mistake again. Sure, it works a LOT better than the GM ABS that came on this car, but it could be... better.

FRESH TIRES, RESET FOR NEXT TWO EVENTS

While juggling customer cars and track tests, we managed to get the C6 into the shop days before the next competition event to look things over, fix one tiny leak, and mount up those fresh 315/30R18 Yokohama A052 200TW tires onto the Jongbloed wheels.



Then upcoming Saturday event was with a new (to me) series (Apex Lap Attack) at my favorite track (MSR 1.7 CCW), which would be the last time I would compete on track in this car on the old Z51 brakes. We also signed up for an autocross on Sunday, with Amy co-driving. This two event weekend is where we would get some test data on the CSL programming.

APEX LAP ATTACK, MSR C 1.7 CCW, OCT 15, 2022

This was the first Time Trial I had done with this group, which they call Apex Lap Attack. I drove the 2006 C6 in this event in their LA4 class (LA1 is fastest to LA5 is slowest), and they have some damn fast folks out there running big aero, Hoosiers, big tire and big power! Some folks only run this series and build for the classes better than me, who just showed up and was classed when I got there.



Amy agreed to join me and helped me during this warm October day - "super genius" me had removed the cool suit cooler since it was "Fall" and I "wouldn't need it", which was a mistake. We got to MSR at dawn, unloaded, checked in, added their unique number boards, and realized I was in the wrong class - they re-classed me to LA4. An old autocross friend of mine Matt Dasheill was there in his E46 M3 on Michelin slicks in the LA4 class, and I wondered how quick he would be?



First session I gridded poorly on sticker A052 tires but was stuck in traffic for the first FIVE laps. My first session time of 1:20.013 was done on lap SIX, which was 3 tenths slower than a month earlier 2 year old A052s. Went out twice in this session (out for 3 laps, came in to bleed pressures, found a gap, and went for 3 more laps) to find that lap. Matt put in his best lap on lap FIFTEEN in his E46 M3, when his Michelin slicks finally warmed up and switched on. He had me by 3 tenths... but I've run that time before, back in August...

continued below

[Fair!]

continued from above

For Session 2, Matt was gridded P1 and I was P2 in our Time Attack group of LA4-LA5 cars, but we agreed to switch places on the out lap so we wouldn't hold each other up (as his tires take many laps to come up to temp). It worked, and my quickest lap was on my first lap in session 2, but I was still .115 seconds off Matt's session 1 time, and I knew it.



I was losing time in braking as well as driving, and this lap above is a hot mess - I almost went off in one right hander, trying to push braking zones. I made another attempt after this lap but was slowing down, as ambient temps were quickly climbing and the A052 tire does not do well on later, hotter laps.



I kept going out in later TT sessions, and in each subsequent session I was quickest in each session, but with temps of 85F and climbing I couldn't improve upon my 2nd session. I needed to get my best lap done in the first lap of the first session, but gridding poorly really wrecked that one. The car had it - I just couldn't wrestle the time free. You can see the per session times below left, and overall results below right.



Finished 2nd in class and 10th overall, a pretty poor showing. This event is where we found that the CSL programming was 100% hype, as the car braked with the exact same max forces as it always had. I was pretty disgusted, and mentioned the braking issues with Louis of GSpeed. He loaned me a special Continental / TEVES Mk60 ABS unit, which we tested the following week.



We loaded up at the end of a long hot day, 2nd step on the podium behind Matt, who drove well and earned it. I was disgusted with my driving and the CSL nonsense. This event further proved that I had waited too long to upgrade to the Z06 brakes. I drank my mini-bottle of champagne and another FULL bottle to drown my sorrows - before pouring myself into the right seat of the F350, where Amy drove us home. We had another long, hot race day the next day, too...

EQUIPE RAPIDE AUTOCROSS, LONE STAR PARK, OCT 16, 2022

This was the first time we autocrossed the C6 and I finally convinced Amy to come with me and drive "her" car. The weather looked a bit iffy, with rain in the forecast, and Amy almost stayed home and slept, but I got her to go - then she beat me senseless in the car!



Remember, this was after a long, hot day at the track where I drove and she didn't - so she was already in a sour mood. And then the rain rolled in and it poured all night, leaving the event site - Lone Star Park - a soaking wet mess. To run our first autocross in the C6 in the rain was a miss, in a car which she has said really was not "fitting her driving style". I just couldn't get her to run the car much on track, and now this?



The courses here tend to be a bit quicker than other sites in the area, simply from the large layout of the site. Bunch of offsets and slaloms, so I figured a Miata would set FTD (and one did). We walked the course in the rain but right as the driver's meeting at 9 am kicked off, the rain stopped.



After the clouds parted the sun popped out and turned the place into a sweat box, but it burned off the water on the surface rather quickly. Only a few Corvair club members got wet runs, and most of the first heat drivers had dry conditions. And Amy and I would run in the third and final heat of the day, after both working in the air conditioned timing trailer (win!).



Amy and I both drove the C6 in CAM-S class, which was Amy's first autocross event in 4+ years. Now Amy has a few SCCA National Championship jackets in the closet, so I was confident she would pick it back up quickly - but damn, she even surprised me. After taking the first run with her in the right seat, she got out and let me take my 2nd and 3rd runs solo. My 3rd run put me in the lead and was - at the time - Fastest Time of the Day.



The run group we were in was a bit too small and the 2 driver cars had to hustle to switch drivers before the next run, and our 6-point harness setup didn't help. So Amy opted to take all 6 of her runs back to back - to avoid switching the seat / harnesses back and forth between drivers. And that worked for her, with warm A052 tires and me tweaking the shocks and tire pressures for her as she just pounded out some amazing runs.



By her 4th run she had beat my 3rd run time, and kept finding time. Bam, Bam, Bam! She was flying, and her 6th and final run of 51.0 was 2nd quickest of the day in the final tally. She then handed the car over to me to take my last 3 runs, and I scrambled to get into the car and quickly got to the line.



OF COURSE IT STARTED RAINING, and I made my last 3 runs back to back with the wipers on high. I was literally the only driver in the final heat to get wet runs, but thems the breaks! Amy's best run is shown below, but my laps in the wet cannot be shown due to the unending stream of expletives.



Results - Amy dominated the CAM-S class and won by .7 sec while I slogged around in the rain taking 2nd. She also took Top PAX for women and set 2nd fastest time of the day, and since the ER club pays out money based on PAX finishes, she walked away with a fist full of cash. This event and win totally turned her day around, from sleepy and grumpy in the rain to a money winner, that's for sure!



The C6 drove really well, and the brakes worked pretty good here at these low speeds. All I did on my first run was drag the brakes while going from grid to the starting line, and they got warm enough to work fine on my first run. I suspect this car could be a really good CAM-S autocross car if someone wanted to do that with it.

MK60 CONTINENTAL/TEVES ABS UNIT - FAIL

Louis at GSpeed loaned me a Continental / TEVES special Mk60 unit, which apparently has some higher braking thresholds. It was supposedly a "plug in swap", but it 100% is not. This requires a special wiring harness, which we found out the hard way. These are not inexpensive units (four figures) but if it could improve the braking of this car, I'd buy one. This was a loaner from the weekend before so the next week we swapped it in place on the C6 and proceeded to try to get it to talk to the car.



This is another internet hyped Mk60 upgrade which we found out does not work with the same harness as the "regular" Mk60. I wasn't going to order another $1200 harness then burn the hours it needed to install that all to test a borrowed ABS unit.



Lots of programming attempts, phone calls and emails, but in the end - a fail. We removed this unit, reinstalled the original Mk60 ABS brick, and got to work on the Z06 BBK install.

C6 Z06 BIG BRAKE KIT - INSTALL

After giving up on finding any magic in the Mk60 units, with programming or special units, it was beyond time to finally time to move forward with the J56 (C6 Z06) brake upgrade on our base model 2006 C6 Corvette. Why? Because the braking forces have not improved with any change in tires (275 RS4 vs 315 A052), pads (stock to R12 to R16), calipers (JL9 to J55), rotors (JL9 to Z51 to Z51 smooth), or Mk60 calibrations (base vs CSL). This car always stops at the same 1.15 to 1.17 peak, period. It's smooth, it's safe, just not changing.




This is a system I looked at early one and it uses a 6 piston front and 4 piston rear caliper designed by PBR. Normally these use small brake "padlets" for every piston - yes the stock Z06/Grand Sport used 20 brake pads. But everyone that makes pads has gone to a normal "unipad", and that seems to work better.



In hindsight this was probably the FIRST mod we should have made to this car, and the prices above are amazingly low compared to the typical BBK - which can be $3000-5000 per axle. I wasn't keen on spending $10K on brakes on a car that had a non-functional ABS system, so I decided to fix the ABS first... and that dragged on for what, 18 months?



Again, this set had the front calipers rebuilt but needed a little more effort to actually make them work - the dust seals at each front caliper were pooched out a bit. Brad handled that and got all 4 corners swapped out with new G-LOC R16 front and R12 rear "monopads".



I had purchased one new "smooth" (not cross-drilled) front rotor from a Z06 early on, and it was only 10mm larger in diameter but nearly 5 pounds heavier than the Z51 rotor. There are some big chunks of 3 weights cast into the Z06 rotor, which we thought about machining off. But in the end we left it alone - don't want to alter too many variables at once here. The old Z51 calipers and pads were used up and were tossed in the recycling bin, but I kept the old calipers.




When we ordered these Jongbloed 3-piece wheels we erred on the side of caution and ended up needing a spacer at both ends to clear the inner fenders. We do this on one-off sets sometimes as there's no way to make a "negative spacer", so we make our best calculated guess and then pull the wheel in 5mm more than we think - to avoid poke - and we can always slip a spacer in to move it back outboard. Well the Z06 calipers are MUCH thicker than the Z51 2-piston sliders, so we needed an extra 5mm front and rear now, for the inner spokes of these wheels to clear the calipers. The 19x10" wheels need the same 5mm spacer, too.



I wasn't going to change all of the calipers and NOT change the master cylinder, so a rebuilt J56 master cylinder was ordered and installed at the same time. It was bench bled before going onto the car then bled when the new calipers and lines were installed.



I mentioned the "missing" rear 4 piston caliper, which was in an unopened box but I guess the delivery folks perfectly opened that one box and took it out and re-taped it. Anyway, I had to buy a new one to replace that, was sent the wrong side, but it was easily adapter to the correct side by moving the bleeders and crossover tube. The last thing we learned was that the brake JL5 lines are the wrong length so we ordered J56 length stainless lines and managed to get it all put together before the next weekend's Time Trial.

HIGH TEMP TIE ROD BOOT REPLACEMENT

One side project that happened during the J56 brake upgrade was replacing the outer tie rod boots with high temp silicone units + some custom stainless steel heat shields. These boots were ordered a while ago and took 3 months to arrive from Eastern Europe, but it was worth the wait. Jason had made some measurements, found these boots, and they actually fit!



If you remember we have burned up tie rod boots continuously on this car, with both the Z5 brakes and it was likely to happen again with the Z06 brakes. The outer tie rods at both ends of the car are sitting right next to the brake rotor, which we have measured 700F and higher temps from.



The replacement outer tie rods were already burning up the new boots - and we never could find OEM replacement boots. These silicone versions were a lot less costly than all new tie rods and should survive better at higher track temps. But we also made new stainless steel heat shields at the same time. These are made from thin 316 SS sheet that sit between the securing nut and the spindle, then droop down over the boot and create a thermal shield between the rotor and boot, with an air gap on each side.



The new tie rod boots and stainless steel heat shields were installed at both the front (above left) and rear (above right) ends of the Corvette. These have worked wonders and half a year later they still look new! This is the new fix for tie rod end problems.

HAWK SENDS MYSTERY PACKAGE

I have been known to promote some brake pad brands over others, but it is because there are clearly different tiers within brake pad offerings' prices and lifespans. I may have built up some biases over the years after having "less than great" results with certain lower cost brands. We tested a number of pads one year on a heavy S197 Mustang track car using Hawk, Porterfield, Carbotech and others. The Hawk HP series street pads were strangely popular within track groups for a while but we could melt them to goo after only a few laps.



As much as you see here on this forum, I post even more on my personal Facebook page daily. A friend from there, John Butler, worked at the US distributor for Hawk and noticed when we switched from the Z51 to Z06 brakes and sent us a "care package" that included both front and rear brake pads for these calipers.



They also included bottles of their HP660 brake fluid, lots of swag, and a funny note! I gave them a thanks and shout out online, but didn't think much about it for a while - but this will come back later as a much welcomed gift that was nice to have for testing on this car (we eventually used ALL of these pads and the brake fluid!)

SCCA TIME TRIAL, MSR 3.1, OCTOBER 22, 2022

October got pretty nuts and between this car and a customer's car I spent 4 days on track + the one autocross, so it was beyond busy. This was an SCCA Time Trial day at MSR on the 3.1, which I had earlier done the Apex HPDE and some sim time to try to learn. None of that seemed to help as I had another poor showing here, and suffered my only loss in an SCCA Time Trial in this car!



Again - THIS is the series we are trying to win for the season in this car, so we had the car on the "big" brakes, fresh tires, and I hopefully knew where I was going now and could improve upon the dismal 2:28 lap that I ran with Apex earlier. The "fuel starve" thing never did pop back up, so that was a relief. There were some teething pains with the new brake kit, but a little pit side repair got everything sorted.



Amy took photos at this event and its nice to see that we have removed the massive brake dive with proper spring rates (above left). Also, the "you are running too much camber" folks had to shut up when I show these laterally loaded images in the fastest corner of the track (above right), where all of that static negative camber disappears. In a perfect world I would run even more camber than what we could reach with the custom offset shims!



My first session lap wasn't exactly setting the grid on fire - I just suck driving on this 3.1 layout. I also forgot my Micro SD card, so video was down for most of the day (I borrowed a card for the 4th session, which we show in the video below). I was a bit disappointed in the fact that upgrade to Z06 brake rotors / calipers / hydraulics and pads made little to no differences in stopping power.

continued below

[Fair!]

continued from above

In Session 2 I heard weird noises under braking, and cut it short after only 2 hot laps, but found a half second to the 2:25.1 range (fixed a loose bolt after this session). Session 3 after lunch went a little better, with a 2:24.6. Still ways back in T2 class from Chris Wheelock (who changed classes to T2 for this event in his C6 Z06) and Cody Loyd (one of the owners at Apex who has an F80 M3 with MCS coilovers we sold him). Still learning this track layout and where to brake in this C6. Of course my AiM didn't work at all in session 3, so I have both no data and no video on that 2:24.698 lap. It wasn't great and you aren't missing much (I came back in early '23 in Koenig's C5 and ran a 2:22 with a non-functional 4th gear synchro, so it was just driving mistakes).



Session 4 I finally had my head right, the video camera was working, and so was the AiM lap timer. I built a huge gap to the car ahead on the out lap and my first lap was looking great, much faster! Then 3/4 way through that long first lap, Anthony's C6 Z06 spun off track. I saw it happen ahead and I could tell he didn't see me coming, so I wasn't surprised when he pulled back on track right in front of me and blocked my lap (SCCA TT in this region does not allow "open passing" in TT, otherwise I would have driven around him). Even with that, plus backing way off to try cool down tires for lap 2, I ran that 2:26.2 lap above (the only one I got on video all day). The rest of that session was fubar, with 89F ambient temps and these damn Yokohamas getting greasy after lap 1.



There were a lot more "heavily prepped" cars at this SCCA TT than I'd seen in the past - like Costas (red C5) and Anthony Jones (black C6) on full aero + Hoosiers in Unlimited 1 class - which were light years ahead of my times in our C6.



Hollis was fast in his U1 classed 720S but Francisco's GT3 RS was only a tenth quicker in his Max3 classed entry. Still, finishing 10th place overall at an SCCA TT event was a new experience, and quite humbling.



The final results are below left (click to expand, as always), where I ended up in 3rd out of 5 entries in T2 class - my worst showing in SCCA TT to date, and my first loss. One of the Max1 cars I usually compare to at SCCA TT events is Brian Phillips and his 2019 C7 ZR1 - above right. He is always on good tires, factory aero, AP brakes and knows many of the local tracks better than I do. He ran a 2:20 lap but I was a solid 4 seconds back - I've never been that far behind him, and have snuck ahead on tracks I know like the MSR 1.7 CCW.



This loss really stung, so I spent some time back at the shop working with AiM Race Studio, then dug into that events' data (but without my quickest session 3 data, as I had an AiM issue). Observations show that my best "rolling lap" (2:24.1) was fully 1 second quicker than my best measured in those 3 AiM logged sessions. That is a continuous lap not using the start/finish as the delineation. Also my best "theoretical lap" (2:20.3) was 4 seconds quicker than my best timed lap - that means I drove fairly erratically and left a LOT on the table. I really have to learn the MSR 3.1 mile course better!



The Lat/Long data was also pretty unremarkable, if not worse - the peak braking in 3 of 4 sessions logged was 1.12g, even with the new "big" brake kit and fresh pads. I was still getting significant brake pad fade in some sections, so we have more work to do. We loaded up to head back after another long hot day at the track, this time with only 3rd place points on the books. There was only one more event to go for the SCCA TT season, at ECR 2.7 CCW in November (another new to me layout I'm still learning). Having missed the first TWO SCCA events of the year and this 3rd place beat down, I was getting worried about season points...

PREP FOR NASA TT

We had a week to make some repairs and swap over to a set of Hoosier R7s for the upcoming NASA Time Trial at MSR Cresson. I wanted to see if the 295mm Hoosiers were better than the 315mm Yokohama 200TW tires - more data to crunch. We also looked at the front brakes, which had an alarming amount of pad wear after the MSR 3.1 event.



One other observation was that the 315mm tire had worn through and kicked off our little aluminum cover plate at the fiberglass inner fender liner structure. Now with the added spacers needed to clear the Z06 calipers it shouldn't be wearing further, but I wanted some buffer here.



The C6's coolant reservoir is the one thing that often gets worn into when the tire rubes on the left front - so we followed some advice I learned from a fellow racer at a recent autocross and we spaced the reservoir up 1/2".



We had these aluminum spacers on hand for some brake cooling kits we sell, and that worked perfectly to move the reservoir up and away from the tire. This is a simple mod that anyone in a C6 should do if they are running wider front tires and have noted the inner fiberglass wear. We will come back later and re-make this aluminum patch panel and reinstall that.

A SOFT SPOT FOR NASA TT

If you have followed my build threads over the years you might remember that I was one of the early adopters to NASA Time Trial back in 2006, and we ran their Time Trial events almost exclusively from 2006-2019. Some of my best results were in TT3 class, which we dominated in the Texas Region from 2013-15 in this S197 Mustang, below.



To make this pig a winner we ran at the LIMIT of the power to weight ratio, ballasting up to take advantage of P-to-W bonuses. We ran max effort aero, cut and flared fenders to runt he widest Hoosier A7s possible (335/345mm), had incredibly good brakes & ABS, and made the car easy to drive so a schlub like me could put it in the winners circle. In 3 years of NASA Texas TT events we had all wins with one 2nd place on a Saturday, but I came back on Sunday of that weekend and won. We also set 16 class track records, and our MSR Cresson 1.7 CCW record from 2013 of 1:17.250 stood for meany years (and our MSR 3.1 mile record from that car in 2013 still stands).



We also ran most of our shop builds in a number of other NASA TT classes over the years, some with differing levels of success. What I have found is that the chassis you start with almost doesn't matter, so long as you maximize the power-to-weight ratio for a given class, ALWAYS run Hoosiers (and A7s where allowed), ALWAYS run the widest tire the class allows, and ALWAYS run the maximum aero the class allows. Whenever we neglected these lessons - that we learned on our TT3 S197 Mustang - we pay the price with lower competitiveness.

NASA TT has no room for casual street cars with no aero, no power or weight misses, and running street tires will often get you laughed off the grid. We most certainly did NOT build this Corvette for NASA Time Trial, and it showed in our lone NASA TT event result, below.

NASA TIME TRIAL, MSR 1.7 CCW, OCTOBER 30, 2022

I wanted to run this event in the C6 in TT3 class, because that's the closest class where it fits - even if we built for SCCA Tuner 2 class with no aero and 200TW tires. I had a new set of 295mm R7s that I had scored for a great price, mounted on another set of 19x10" wheels, but that wasn't exactly a TT3 competitive setup these days. I really just wanted to just see my NASA TT buddies, and see how the C6 would do on R7s for the first time. Would it be quicker than the 315mm 200TW Yokohamas? The same? Slower? We would soon see!



Due to the extremely busy month of track events and testing in multiple cars, I only entered a single day of a 2 day NASA TT weekend (Sunday) - which meant I would start at the back of the grid, as the rest of the field had a full day of lap times in the books to grid from. I had to get there early for a NASA TT log book and Annual Tech, but Hank passed the car with flying colors. We actually were pretty close on the TT3 class 10:1 pounds per horsepower ratio, which was just dumb luck.



First session was REALLY tough, starting at the back of a 29 car field - behind a lot of TT4, TT5 and even TT6 cars. Needless to say I got a lot of passes in, but never had a clear lap - still finishing with the 7th quickest time out of 27 cars that ran that session - and that 1:21.0 lap moved me way up the grid. Of course TT3 was the biggest and fastest class of the event, with 7 cars (almost 1/4 of all TT entries were in this class!)



Barely made weight after 1st session (+9 lbs over) so I added the cool suit cooler and topped off the fuel tank for extra ballast. Running the whole session still made me sweat, even at 51F ambient. In session 2 found a second, 1:19.962, only need three more seconds to catch the TT3 leader!



After the 2nd session I was 8th quickest with only TTU and TT3 cars ahead of me. Blake Pomyyal's E92 M3 was out there topping the time sheets overall with a new TT3 class shattering record of 1:16.262, a full second ahead of my 2013 TT3 track record - the class has gotten stupid fast in the last decade!



Session 3 was starting off well, but the R7s take 3 laps to come up to temp and that was a bit frustrating - as the front of the field would start catching the back within about 2-3 laps. I was fighting for a better lap as temps were rising, which might help these tires, when we saw waving yellow and black flags and we all had to come in. Turns out that two TT3 racers "had a moment" which cut that session short, and also cancelled the 4th TT session. So I would have to sit on that 1:19.962 lap from session 2 - which is 2 tenths slower than what we have run in this car in this setup on 315mm A052 tires. Hmm...



Dan Parmelee's C7 Grand Sport was one of THREE cars in TT3 class that ran a nearly identical 1:18.2 time - 2nd through 4th places were decided by hundredths! Blake was way out in front with the TT3 win and track record, but I was way back in 5th out of 7 "in my own second" with that 1:19.9 crap lap. Sadly that time would have won TT1 or TT2, both faster classes, but that was just a lack of attendance. Oh well, it was worth a shot. Brakes felt like crap anyway - shocker - so new changes were to follow in the coming weeks.

"HOOSIERS ARE ALWAYS FASTER THAN STREET TIRES"

This is another commonly made statement that needs a LOT of caveats, as we have seen on multiple cars now. While I was disappointed that my best time on 295mm Hoosiers (1:19.962, NASA TT Oct 30th), it also couldn't beat my best street tire time on 315mm A052s (1:19.702, SCCA TT, Aug 13th). It is all pretty dang close, but I was expecting a 1 sec drop with the "purple crack", as we have seen in the past.



And sure, the 20mm narrower 295mm Hoosiers being on a 19x10" wheel didn't help, compared to the 315mm A052s being on 18x11/18x12" wheels - yet another variable. In the end, when you compare the peak lat / long g trace data from my best laps on both tires, they are almost identical. Would an equally wide 315mm Hooiser A7 make more grip? Likely, but without infinite resources to test this theory, we'll just have to speculate.



In the extensive "street tire vs race tire" testing we did in the 2018-19 seasons on our 2018 Mustang within NASA TT weekends - running 200TW Bridgestone RE71R tires on Saturdays and 315mm Hoosier R7 or A7 tires on Sundays - we showed a very consistent 1 sec improvement on Hoosiers. But the A052 has gotten faster than the RE71R, and a lot closer to the Hoosier in outright pace, and it sure heats up quicker than the R7.

WHAT'S NEXT?

I better stop here, as we still have a bunch left to cover for 2022 plus all manner of changes we made in 2023, leading up to a sale of this car that will happen soon.



Next time we will cover the last 2022 SCCA Time Trial event (ECR 2.7 CCW) from November plus another NASA TT in the C6 in December. We also show a few updates with brake cooling (which made a big improvement!), a manually controlled muffler bypass setup, CNC ported heads / cam / intake / throttle body upgrade, new ARH Long Tube Headers / injectors / LGM carbon airbox / custom dyno tune, the carbon lip went back on, we had some paint work done to the car, then got it cleaned up and pictures shot for the upcoming auction.

Thanks for reading!

Terry Fair @ Vorshlag

[Fair!]

Project Update for November 10th, 2023: Another bit of time since the last post in the C6 / Project New Balance thread, and a lot has gone down. Our narrow body C6 is already prepped for sale and has seen its last track laps under our ownership. But this build thread still has races to cover, parts to explain, and prep work to go over. And as you might see, I've merged 3 threads into one: everything for all of our C5 & C6 development



This time we will cover the last few competition events in the C6, as well as a big round of power upgrades I insisted on - then never got to track test! It makes 441 whp now, +80 whp over what it made stock, yet still runs super quiet and smooth.



The last few months have been a whirlwind - we bought two new vehicles (2023 Bronco and 2024 Mustang Darkhorse - below left), my main race car (2015 Mustang with 454" LS V8 - below right) finally had a breakthrough and is winning races left and right, and Vorshlag has cranked out some cool aero jobs for customers. We've also revived another C6 build - which I will talk about later on in this same thread. We aren't done with C6 development - not by a long shot!



Let's cover the final upgrades, races, and updates to this narrow body C6 before we turn this thread into a build for our widebody all carbon C6, #ProjectRampage. Let's pick up where we left off - October 2022!

SPACER MISTAKE = REAR FENDERS CRACKED

One of the guys that worked for me made a big mistake when prepping the car for the NASA event in October 2022 - he put the wrong spacer package on these 19x10" wheels and 295mm Hoosiers. These are the same 19x10" wheels as we have the 275mm Hankooks on (our original control tire) but when running the 295mm Hoosiers they needed a spacer in the rear. He stacked two sets of spacers out back, and it allowed for some poke... and that allowed the tires to contact the rear fenders.



I figured this out after the first session at MSR during a race weekend, and did some changes in the paddock to prevent further damage - but by then the rear fenders were cracked. It would be different if this wasn't the 4th time the same tech did this sort of thing that cost me paint and body work repairs (he no longer works here). Anyway, those rear fender cracks along with some prior paint imperfections that came with this car are what prompted me to spend several thousand dollars on a partial respray, which I will show later in this post.

MOROSO C6 COOLANT RESERVOIR

Another thing that kept happening with the giant 18x11" / 315mm front tire and wheel package was wearing the tire into the plastic coolant reservoir under the hood. The front tire that came with this car was a 245mm, so a 315mm just needs some real room.



This is a common issue on all C6 cars running a wider tire up front - the left front tire often rubs through the fiberglass inner fender at full lock, then it can touch, wear through and puncture the plastic coolant reservoir, shown above right. We had that happen once and replaced the reservoir already, but it quickly got nicked again by the fat 315mm A052 up front.

That's when made an aluminum "tire shield" (above left) to cover that small wear hole, but the tire ripped that off a few events later. The prevailing wisdom is to move the reservoir and just "let the tire eat". We spaced the reservoir up 1/2" with some aluminum spacers we make, but it still made me nervous with the nicked plastics.



Instead of buying a 3rd plastic reservoir, we found this Moroso fabricated aluminum reservoir - and I bought that for my peace of mind. We also spaced that up with the same aluminum spacers to gain more room to the tire. The shape of the tank also includes extra clearance where a fat tire likes to eat, shown above right. A quality piece that should be on any C6 track build with fatter front tires like this.

NEW C6 Z06 MASTER CYLINDER

After the last October Time Trial we kept fighting a crappy feeling brake pedal with the new Z06 brakes, even after several fluid bleeding sessions. So we tried a better brand of new master cylinder, again specified for the J56 / Z06 brakes.



This AC Delco Professional brand master ended up being a new and not rebuilt part, and that bled perfectly as soon as it was installed...



That made for a better brake system feel on track at the November ECR event, shown below, and is what we will stick with. Name brand parts are always better than rando import brands!

SCCA TT @ ECR 2.7 CCW, NOV 19, 2022

This event was COLD (27F-47F) and had a hectic start. We arrived with our narrow body LS2 powered 2006 Corvette C6 only 5 minutes before the 8:15 am driver's meeting, and had all manner of problems to fix before going out in the first track session at 8:45 am - in 34F temps!

Amy fixed a flat tire on the car in paddock while adding the right wheel spacers, torqued all of the wheels, set tire pressures and brought the car to grid while I ran up the hill and attended the mandatory driver's meeting. I missed the first 2 laps in session 1 - but got a traffic free stint and set 2nd fastest time up to that point (as usual, many folks are really slow to get going).



This was my first ever time to drive at the new 2.7 mile CCW course at ECR - the last time we ran here going this direction in 2018, it had a different 2.5 mile layout. With virtually every corner changed I spent 4+ hours on the simulator with the #HashtagRacecar map of the ECR 2.7 course the week before, and then learned the course during the rest on this Time Trial.



I was shocked to be running 2:03 times in the 2nd session (that's relatively quick), and many others couldn't believe that a little T2 car was that far up the grid. Session 2 and 3 produced nearly identical times (see above left), but early traffic in both sessions held back the car's potential (only .055 sec quicker in session 3). Traffic was horrible - I even tried starting from the back of the TT Red grid in session 4, but was still held up and had a poor showing there. That means my session 3 video below shows my best attempt with a 2:03.7 lap. A 2:02 was in the car...



The video above is from the 3rd session, where I tried 3 different times to find a good gap to put a lap in, but "faster" traffic gridded ahead of me kept holding me up. Some folks don't get quick until their 4th-6th lap, but my driving style (and basic TT strategy) plus these A052s like to get it on lap 1.



All season I fought this battle of gridding behind folks "slow to get going" and it definitely held back the car's potential this day. Plenty of my normal driving mistakes kept the car from touching a 2:02 lap, but this 2:03.7 time in our little LS2 powered car ended up 5th fastest out of 39 TT entries. We won the T2 class here and that secured the regional T2 championship (whew!) for 2022.



This was the event where we started to meet more of the SCCA TT regulars, and the 5th overall finish helped folks realize who we were and THAT helped us in the 2023 SCCA TT season get a little more recognition and room on track, even if it was in a different car. We also got to drive the "EQUALIZER" charity car, this 2020 Toyota 86 shown above. We donated Vorshlag camber plates to this car and I dove it again in December (it was over 3 seconds faster with camber).



This again was my first time running the ECR 2.7 CCW course and I really liked it - I would later come back and run here many times in 2022-23, and its one of my favorite layouts now. I'm running there in a month in Trigger and hope to beat a 1:55 time in the Mustang. This was a weird day and I noticed a tire was flat on the F350 while fueling up at Buc'cees on the way home, and we fixed that before it let go. Amy was the star of the day - just coming to support me, and literally saved my day. Her 2023 BRZ showed up a week later and we brought it back to ECR for some more events.


That win at SCCA event #7 took us over the top and secured the 2022 Texas Region SCCA T2 championship. I missed the first two events of the year (car wasn't ready!), then won 4 of the next 5 events. My loss at the SCCA MSR 3.1 was the worst showing all year - I'm still learning this track. At least in 2023 I did win Max1 and set FTD at this 3.1 SCCA TT event. Lots of real world practice + simulator time + a faster car helped me finally get it.



On February 4th, 2023 we went to the Annual Awards Banquet for the Texas region SCCA. We got to see friends and fellow competitors, eat, drink, and receive our award for winning the Tuner 2 championship. How much did we spend to win those 4 races? More than $20,000, but it's best not to add these things up. We had a lot of fun, I got a lot of much needed seat time (after a few years out of TT), and proved that a narrow body C6 could hang with and beat the turbo M2/M3 BMWs, C6 Grand Sports, Shelby GT350s, and Camaro 1LEs. If we didn't get the Mustang running - this C6 was going to do it again in 2023!

NASA TT @ ECR 2.7 CCW - DEC 3-4, 2022

This was the final NASA race weekend of the year and Amy and I drove 3 different cars across the two days of Time Trial events. I ran the C6 in TT2 class Saturday, fighting traffic, a long brake pedal and worn out front pads - on the 295mm Hoosier R7s. Why didn't I run the 315mm A052 tires?



That is a good question, as the Hoosiers were a solid TWO SECONDS SLOWER than the A052 street tires. There were a lot of factors at play to explain this, namely the colder temperatures, crowded sessions / very bad traffic, and my inability to get any heat into these tires to switch them on. If we had enough brake pads for day two I was going to swap on the Yokohamas and shoot for 2:02 times.

Alas, this was the 3rd and final event on these G-LOC front pads, which died an early death on these Z06 brakes. I explain why below - wasn't the pads fault, just my driving style and CRAP factory brake cooling. Somehow even being 2 seconds slower than the month before on street tires, I managed 2nd out of 7 in TT2 class and set the 4th fastest time of the weekend.



There was also some nonsense that caused me to miss my first TT session, which hurt my grid placement in the subsequent sessions. I was on grid on time but still putting my belts and gloves on, so I waved the grid marshal to let a few cars behind me go ahead. I was ready when they got to the end, and I communicated a "thumbs up" that I was ready to go.

But the grid marshal held me and said that I "wasn't ready" and "would slow up the field" if he sent me out. I jumped out of the car and pointed - the cars are still leaving pit lane and its a 2.7 mile course with only 35 cars! Nope, he booted me off the grid. Boy I was super pissed, and had to go out in an HPDE session to get some seat time. Complete bone head call and I took it up with the NASA TT folks later, but it wrecked my whole day.



This is because I had to start at the back of the grid for the 2nd TT session, and like in the entire season with SCCA TT, I got stuck in massive traffic immediately. Massive amounts of traffic...



This video shows 4 laps from the 2nd session, where I started dead last. It is super frustrating to watch as all manner of cars hold me up until lap 3, where I finally had one guy who let me by. But there was a "moment" with the rear tires that almost caused me to loop it - and that was my best time. UGH. Lap 4, more traffic, and by lap 5 I had no brakes.

In the next session I was finally gridded P4 but STILL fought traffic ahead of me and the brakes only got worse. This car just did not get checked out properly at the shop before this event - it should have been on new pads and fresh fluid, and it would have been a much better weekend.



I also drove the Equalizer 2020 GT86 in 3 timed laps, 2 of which were blocked by other racers. On Sunday, with the brakes totally fried on the C6, we brought Amy's 2023 BRZ, got it log booked, and I ran it in TT5 class in stock form - fighting traffic and killing the OEM front brake pads in the process. Amy drove this car in 2 sessions of HPDE4 to get some seat time.

A frustrating end to the TT season, where I had expected to run a 2:02 or better lap in the C6, but worn brakes, the grid marshal block, and just slow "early lap" traffic blew all of those opportunities. Bah!

PREMATURE PAD WEAR + BRAKE COOLING UPGRADES

After only three Time Trial events with the big 6 piston front / 4 piston rear C6 Z06 brakes, the pads and rotors were trashed. I couldn't even manage a 2nd day at ECR TT above, since the pads were just DONE. I wondered what the heck was going on, because the braking forces just weren't all that great - so we dug into the data and looked closely at the pad wear.



The outboard pads wore more than the inboard side, so it had to do with brake cooling. We triple checked the calipers and they weren't frozen or bound up in any way. It was time to really tackle the brake cooling deflector design, which we had put off for too long.



We started by looking at the factory C6 Zr1 brake cooling deflectors, which are plastic and bolt to the (unique) front lower control arms with two threaded holes. And while we could have drilled/tapped the arms on our C6, we wanted to make something we could sell that would be easier for our customers to install. Yes, that is the whole point of this build - make parts people can buy, which are actual solutions to problems. Brake backing plates and hoses are so 1960, and these deflectors DO WORK on the many other cars we've built and tested them with.



We got pretty far on the ZR1 style deflectors, but I simply refused to make people drill holes in their control arms. So we modified the lower flap to be bigger and further from the front swaybar. We also kept the mounting simple and it attaches to the front swaybar endlink, as shown.



We also added a "tang" that locates the unit relative to the control arm. It comes down to one nut that holds it on, but the tang keeps it from rotating.



We also updated the tie rod end / ball joint heat shields, which are made out of stainless steel. We never released these "tie rod boot shields" as a product, but might if the need arises. Sure keeps the ball joint boots happy.



I would go on to do some track testing of this brake deflector and it made a HUGE difference in both performance and brake system lifespan on track. With these in place and even just the stock brake cooling hoses the brakes just last and last, whereas before I was lucky to have a solid pedal after 3-4 laps. This C6 brake cooling deflector kit has been a solid seller and we should have a version tested and released for the C5 soon.



The old pads were also heavily tapered, and with the DTC-70 pads that John from Hawk sent us on hand (he now works for Apex Wheels, and we've worked with him on some wheels for our track cars already) we rushed those into duty for the front brakes. Saved us having to rush some pads in for the next event!

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The "lightly used" front rotors that came with this used C6 Z06 brake kit were now trashed, but we sourced some "solid faced" replacements from Centric (no cross-drilled or slotted nonsense).



And like the factory brake rotors, the aftermarket replacements are all made only for the one corner of the front axle - with backwards vanes on one front location. That's been how its been for a long time, and they still work. Blame GM, don't hate on me!



Had high hopes that this cooling solution would finally give us solid, reliable brakes for this C6 (it did!). Two years I have been babying the brake pedal, never knowing if it will lock, fade, or stop.

NEW REAR MCS RESERVOIR MOUNTS

It was getting close to time to start prepping this C6 for sale and one of the open tasks I had was making "prettier" mounting brackets for the Motion Control Suspension remote canisters.



I was never happy with the rear mounts, which were down inside the two storage cubbies and just zip tied to some factory plastics. Started with some templates...



Ended up with these curved mounts that bolt to the rear fenders, where the targa top brackets normally sit. Clean install out back now. The front was cleaned up months earlier.

C6 TRACK TEST #12 - DEC 29, 2022



This was a busy day but beautiful weather for testing (55-69F), after some precip burned off. We went out to MSR Cresson with the C6 for the car's 12th dedicated test and our 2023 BRZ's 4th track test. I drove both the 2006 Corvette on the 295mm Hoosier R7s and the 2023 BRZ on 225 Falken RT-660s, and Amy also took laps in the BRZ.



The BRZ was using MCS dampers on the 225mm Falkens, and the MCS shock change picked up 3 sec over the last test. Big improvement! On the C6 and we tested brake cooling with an 8 lap then 11 hot lap stint - best they have ever been! I also drove Scottish Joe's C8 Corvette, which was eye opening.



Up until this point we never could manage more than 2-3 hot laps in the C6 before the brakes overheated - with 3 different brake systems (base, Z51, Z06) and all manner of track worthy brake pad compounds. Well this time with our C6 brake cooling deflector the brakes were OUTSTANDING! I did an 8 lap stint, then an 11 lap stint, and the brakes never let me down, never lost bite. We also saw the highest braking g readings (1.19g) that we have seen in 2 years of trying. WOO!!!



There was a lot of traffic, and with the R7s the lap times were kinda "meh", but I could run a string of 1:20 laps with ease, as the brakes never went off like before. Big success, right at the end of this project. Wish we had the time to do the Z06 brakes + cooling a bit earlier. Oh well, the next owner is going to benefit from all of this hard work and testing.

DE-STICKERING THE CORVETTE - PREP FOR PAINT

Takes a few hours and some heat to get these old decals off. Best bet is to park the car outside in the sunlight on a warm day - it was not a warm day here, so we did this in the shop.



Man that was painful to watch - all of those decals were part of the last 2 years' history with this car, and I had a feeling this car might never get another class letter / number / series decal while we owned it. But it was necessary to get the car "naked" and ready for the painter...

CORVETTE GETS PAINTED (60% OF THE PANELS)

I trailered the C6 over to our friends at Heritage Collision, who have repaired and painted 20+ cars for us and our clients over the last 15 years.



The owner there, Shiloh, knows that I'm pretty picky for these "shop builds" that need to be sold - I want them to leave our shop in better condition than when we purchased them. This C6 had some "legacy" scratches in the front and rear bumper covers and front fenders, the two rear fenders that got bonked when goofball put the wrong spacers on, and there was some tire klag hits on the roof panel where it needed to be fixed, too. He marked all of the issues in tape and they got to work.



All of the front and rear lights came out then the two bumper covers came off, as these both needed to be spiffed up and resprayed. The rear fenders came off too (luckily that is easy) for repairs then a full respray, and the roof needed paint - but it is easy to remove.



I didn't rush them but at the end of February they had the C6 all painted, reassembled, paint corrected and detailed. It looked better than new!



Carefully brought this back in the trailer and we got to work on the power upgrades that had been planned long ago...

CNC PORTED HEADS, CAM, INTAKE MANIFOLD, 103MM TB LGM COLD AIR, LGM HEADERS

Now don't ask me why I decided to do this, but I had delusions of keeping this C6 for a "backup car", as our LS swapped Mustang was being a real pill in the Spring of 2023.



And with my ties to HorsePower Research, they hooked us up on these CNC ported LS2 years, spec'd out a tiny hydraulic cam, and then I had this cathedral port FAST LSXR 102 intake and 103mm Nick Williams TB, injectors and fuel rails from my Mustang...



See we had a bit of an issue with the cathedral port 383" LS6 we built for my Mustang, and we decided to upgrade that car to a 454" LS7, so I had all of these brand new parts for a cathedral port LS engine. So the C6 got an 80+ whp bump in power.



These are single pass CNC ported LS2 cylinder heads, built by HorsePower Research with some really good valve springs, new guides, and all of that. These were installed with ARP head bolts, shown above. The Comp Cams hydraulic roller was spec'd by HPR and it is barely audible when its running, but adds more lift on a wide lobe separation.



The LS2 intake, stock injectors, fuel rails, "injector covers" and 90mm throttle body came off (and sold for good money) and on went this FAST LSXR 102 intake + 103mm Nick Williams DBW throttle body, and FAST fuel rails (more on that in a second). The entire intake manifold assembly came off my Mustang's 383" engine, and was identical to one we put on a customer's CTS-V race car with a similar 383" LS6.



I never liked the SLP cold air kit, so we upgraded to this LG Motorsports carbon cold air kit when we changed the intake and such. Really beautiful piece that fit better. We had to tweak the mounting ears a bit as these are made for the later LS3 C6 cars.



While at LGMotorsports we picked up a nicer set of 304 stainless long tube headers. These have 1-7/8" primaries and 3" collectors, and we opted for their X-pipe with optional catalysts and track pipes.



We kept it simple for plug wires, with a set of 10.4mm Taylor wires and DEI heat sleeves that worked well with the new headers.



Fuel Injector Clinic 50 lb/hour injectors (ISC302-0525H) also came from my Mustang's engine, again with minimal run time. We started with some FAST fuel rails but had an issue with the brackets (NEVER USE FAST FUEL RAILS) and upgraded to these billet Deatchwerks rails, which have integrated brackets and are very beefy!



It all came together and we had it tuned, which I will talk about next. No leaks, issues, or problems - just lots of glorious noises.

SCCA TT MSR 1.7 CW - APRIL 1, 2023

We had the car tuned in March and it made good power, and I got permission from Amy (it is technically "her car") to drive the C6 (just painted) in one last Time Trial event, the first Texas Region SCCA TT event of the year. On April 1st.



Well I sure felt like a fool when we unloaded the car, got the decals on, got all of the timing gear installed, and drove to grid... only to realize we lost throttle control. I missed the first TT session as I putted around Motorsport Ranch looking for a diagnostic tool. Larson Motorsports had a SnapOn scan tool and we could see the throttle pedal commanding the opening percentage, but the throttle body wouldn't open. I could drive around in the paddock but with no throttle opening past idle, eventually I just stuffed the car back into the trailer, utterly disgusted.



I was moping around, driving Amy's BRZ in Max1 class slowly (which was the class that my Mustang was built for, which I would finally debut later in the year), but my main Max1 competitor for 2023 Stan Whitney saw me in the trailer before the 4th and final TT session. It was a hot day and he told me I could drive the last session of the day in his GT500.



This is a 760 hp new GT500, with a custom DSC magneride tune, 7 speed DCT sequential, some lowering springs and lots of camber. I hopped in, took 3 laps, and won Max1 class and almost set FTD. Dang that 4200 pound Mustang was FAST and gave me hope that we might be this quick in our own S550 race car later in the year (we were). But the lack of throttle function in the C6 was beyond frustrating. It could have been as fast or faster with the added power!

TUNING THE NEW LS2

We went through two tuners getting this C6 right with the new power mods, and I paid for both tunes. The first tune made good power but the throttle body mysteriously quit working on at that SCCA Time Trial event, which was my last opportunity to drive the car on track.



The tuner wanted to blame parts, so we "fired the parts cannon" and tried a different pedal and throttle body, plus checked all wiring. The problem still persisted. So I called a "gunslinger" tuner that can make house calls, who came by the shop in early May. The "fun" I've had with tuners in 2023, man I could write a book!



He did a "street tune" - where I drive and he makes changes on a laptop in the right seat. We did about 30 pulls and had it 95% right when the FAST fuel rail decided to YEET itself free from the engine. We both smelled the fuel leak, pulled over, and we made a hasty repair roadside. That's when we went with the DW fuel rails - I won't make that mistake again. Later in September I rented dyno time at LGM and got these pulls.



Made within 1 hp of what it made in April, but this time with a working throttle body. Oh well, something new we know to look for. Sure wish I could have gotten that Time Trial at this power level, I'm sure it would have been glorious.

OPTIMA BATTERY UPGRADE (LASTED 4 MONTHS!) THEN REPLACEMENT

During the engine work phase in early 2023 the old wet cell battery finally went kaput. My problem tech had wired in a solenoid to be powered on all the time and that battery draw killed it. So we replaced it with this new Optima Red Top. It lasted 4 months.



I only bring this up to point out a pattern of failures we have had since the Pandemic - this is one of NINE Optima or Odyssey AGM batteries we had that failed prematurely in 6 different cars.



Brad re-wired the entire exhaust solenoid system, and re-plumbed it for cleaner vacuum hard line runs. We swapped the problematic Optimas with O'Reilys 72 month wet cell "Super Start Extreme" batteries on many of the problem cars, and all of the problems .... went away.

CARBON LIP GOES BACK ON

After the C6 came back from paint we had a lot of little tasks to make it more sell-able. But the nose was too boring, frumpy. And I really regretted taking off the carbon creations front splitter lip. But back when we put that on we had two reasons to pull it off: 1) it wasn't 100% legal for Tuner class. 2) This thing effectively blocked the factory brake cooling inlets. But now that we had a heads / cam package on this car it wasn't going to be Tuner class legal, so...



I tasked Brad with cutting holes for our little aluminum brake inlet scoops, which REALLY worked well at track test #12. So he marked the factory inlets in the lower cover onto some paper templates...



This paper template was transferred to the carbon lower lip, and he sawed out the openings with a jig saw and cleaned up the edges. No going back now, we had to make it work or this splitter was junk.



The old aluminum scoops were reinstalled and the lip was installed with about 30 rivets, like before. This time was easier as the holes were already in the lower bumper cover. And damned if it didn't look better with that change!



This splitter lip doesn't impact the flow from the brake cooling inlets with the holes cut and scoops added, so it should be a net benefit with a tiny bit more front downforce. and it looks cool.

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EXHAUST BYPASS SOLENOID + SEAT HEATER SWITCH

We added several switches to the old "ash tray" section of the center console (like, do people still smoke inside cars now?) including the two mode seat heater switch and this dual USB / volt meter. The ABS trouble light for the Mk60 also went into this now fixed panel. But something new was added in January of 2023...



This was when we put the "stealth mode" switch for the C6 Z06 muffler bypass. We had been running these 3" mufflers with the new LGM exhaust for a while



This was done a while ago and since then the plumbing and wiring was re-done, but this shows the video of the muffler open and closed...



Pretty amazing difference and more and more cars are coming with these "internal bypass" valves, like our 2024 Mustang Darkhorse. On this C6 it makes a huge difference in sound levels at idle, cruise and wide open throttle.

PREPPING C6 FOR SALE / INTRO

The C6 is just too perfect to just let sit and gather dust. When I was over-ruled on keeping the Corvette, we had the car painted and detailed in February, March was when we did the heads/cam/intake/tune, and then April and May was spent doing some final repairs and detailing the car.



It didn't take much, as we always kept this car super clean and stored indoors. But once the final detail and vacuuming was complete, it was time for good "for sale" pictures.



Brad took dozens of pictures of the car inside / out / underhood, then the C6 sat under the car cover waiting for me to finalize the car for sale page...



You can see all of this here: https://vorshlag-store.com/pages/for...jectnewbalance

WHAT'S NEXT?

The ad page I made worked very well and it only lasted a few days. The C6 might already be sold, but I will confirm shortly when the funds arrive.



We have a number of sets of wheels that were leftover from this narrow body C6 project - I will post those up shortly and/or repurpose them for another few GM projects we have in the works. We will know more soon.



We also have decided to revived our all carbon C6 Z06 chassis, Project #Rampage (see build thread here), and we will continue to use this thread to chronicle that as it starts to move back into the shop schedule. I also merged the original ProjectNewBalance + C5 Development + C6 Rampage threads with this one - let's hope I didn't screw that up.



Thanks for following along on the Narrow Body C6 - it was a fun build, we learned a lot, and got some cool parts out of it. Going to make somebody a very nice race / street car. We will keep adding to this thread on the C5 work we've done as well as the Rampage project we're about to kick off again.

More soon!