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Unread 08-02-2017, 10:24 AM
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Default Vorshlag C6 Corvette Development + Shop C6 Z06 Race Car (Rampage)

Project Introduction - August 2nd, 2017: For some time I have been meaning to create a "development" thread for C6 generation Corvette (2005-2013), to show the parts we have built for and work we have done to these cars at our shop. On July 27th I purchased a 2007 C6 Z06 chassis, so I needed to start a "C6 build thread". Instead of two separate threads this will function as both. From time to time here I might also touch on some C5 and C7 Corvette work, as those generations are similar enough to the C6 that there is some crossover.



We purchased this C6 Z06 chassis for a number of reasons. Like to develop things like a proper roll cage for this aluminum chassis, to perfect some new wheel fitments, to test out new engines/components, and eventually to build it into a dedicated road race car. But it is meant to be a test platform for our own and partner manufacturers' products as its first priority, just like all of our shop owned cars.

Potential Snowflake Trigger Warning: In this thread I will not be "self censoring" the contents, to make it more palatable for cross-posting into multiple forums like I usually do. Why? Well to be honest most of the car tech forums where I used to share threads on are either dead, broken, have become pay-to-play and just full of shills, or have so little traffic it is not worth the effort. This is written for the Vorshlag forum, but if there are some remaining car forums that are looking for uncensored tech, it will have: water marked pictures, links to products on our website, and rambling posts covering multiple cars. For the first time in 15 years this will be a raw, no-holds-barred post. Easily triggered readers - this thread is not a Safe Space! Remember: I'm not putting a gun to your head and making you read this.



This build and development thread, like everything we do, has the end goal in mind of improved road course and autocross performance, along with additional horsepower. Those are the things we care about are: turning, stopping, and accelerating. We won't be discussing car show upgrades, or stereo tweaks, just things that make a C6 better in competition motorsports use, building/fabricating parts, testing and driving these cars on track.


Left: The C7 Corvette uses an aluminum chassis like the C6 Z06. Right: C6 Z06 on 315F/345R Hoosiers + aero

I will open this first post with the reasons why I have NOT had a C6 Corvette for the past 12 years, then we will cover some basic aspects of the C6 chassis that are noteworthy. I will then veer off into a 2016 track test where I put some laps in a stock '12 C6 Z06 vs a '17 C7 Grand Sport (and a '13 1LE) to get a baseline lap time, which we can compare against when we drive other modded C6 Z06s on track (including our build, some day). Then I will cover the rolling chassis 2007 Z06 we purchased. I will also show some other C6 Corvettes we have worked on and developed parts for in the past several years. I won't cover everything C6 related we have done in my first series of posts today, but will instead insert the various C6 parts and past work into future posts.

SELF-IMPOSED C6 OWNERSHIP BAN

So I initially wrote an eleven paragraph section explaining the reasons why we sold our 2005 C6 Z51 12 years ago - a car that I absolutely loved for its performance - and then I waited until 2017 to buy another. Other than for my own benefit nobody would have cared to read those 11 paragraphs, so I re-wrote that to be extremely brief.

In 2004 my wife saw the C6 at a car show and loved it. We custom ordered a 2005 Corvette Z51 6-speed with no other options, got it within the first month of the C6 debut, drove the heck outta the car for a year, and really enjoyed it. We autocrossed it a bit (on 11" wide wheels with 315 Hoosiers) and that car and I really clicked. In the words of Jim Carrey: "I like it a lot."



After a year of ownership we came to a cross roads: we were building a new house/shop, Vorshlag was just starting to take off, and since the main product we sold at the time was spherical camber plates for McPherson strut cars it didn't make sense to own a Corvette that couldn't use these parts. Since the C6 was brand new and cars were still very scarce we sold it for what we paid for it. It was a tough call but selling that C6 really helped us move Vorshlag forward in 2005. As a result I have been racing "McStrut" cars almost exclusively for the last 12 years. A dozen years of waiting... for another.

WHAT MAKES A C6 CORVETTE WORTHWHILE?

I'm not a "Corvette person", or a devotee to any marque or model. I don't go in for any "car worship", but instead value a car for simple reasons: power, handling, brakes, grip, drive-ability, and weight. I don't really care what badge is on the outside, what "prestige" a car maker has, as long as it delivers the goods. Part of our business is making "hybrid" cars using things like a German chassis, an aluminum GM LS engine, Ford differentials, brakes from South Africa, suspension from Holland, etc. We try to take the best "performance/price" parts from all over the world and put them into one car.



The C6 Chevrolet Corvette happens to have a lot of really good "parts" all in the same chassis, from the factory. And the Z06 model is amped up even further: hydroformed aluminum frame, *carbon fiber bodywork (*some panels), ample tire room, 7.0L 505 hp aluminum V8 with *dry sump oiling (*only a 2 stage pump, but better than a wet sump), decent brakes, and a low drag body shape. It runs low 11 second quarter miles and can do 200 mph top speeds in stock form. The strong, rear mounted transaxle (see below) shifts some weight to the rear, which is always good on a front-engined car. Its relatively light, too.



There are some negatives as well - poor seating position/visibility & limited interior room (making racing seat and cage installation difficult) to name two. Having a composite body that bolts to a full frame is supposedly less efficient than unibody construction. Is that last claim proven? We have a good test in mind to prove or disprove this unibody vs full frame weight theory.

We will compare the final weight of my 2007 C6 Z06 race car build (below left) against a similarly prepped, carbon roof/hood equipped E46 M3 (below right). Both builds are getting large displacement aluminum LS V8s, both will have a 335mm front and 345mm rear tire, both will be caged, and both will get similar aero upgrades. In the end the scales will show which is lighter and which has the better front/rear weight bias. I'm actually pretty excited to see both of these being built side-by-side in our shop.


Which V8 race car will be lighter? The body-on-frame C6 Z06 or the lightened unibody BMW E46 M3?

Every car I have purchased since 2005 has had some business purpose for Vorshlag: as test mule/product development chassis and usually as a marketing vehicle in some form of motorsports competition. I violated the first half of that rule (we don't make any C4 Corvette parts) when I purchased this 1992 Corvette below back in 2014 (Project Dangerzone) - which we built just to prove a theory. Turns out that hunch was well founded and we set several track records in the car, got noticed by NASA officials, and they threw weight at it the next year. Had a lot of fun with that C4 but there were some Corvette specific challenges we had to learn to solve, like the roll cage installation. Landing cage tubes onto a full framed car - while passing through a composite body - was tough.



We want to test our cage building techniques on this Z06 - a car with an aluminum frame, no less. We have seen some sketchy cages done on C6 and C7 aluminum chassis cars and want to see if we can come up with a better solution. So "better cage development" will be one of many goals for this chassis.

BASELINE ROAD COURSE TESTING: STOCK C6 Z06 vs C7 GRAND SPORT!

If you have read any of our other detailed build/development threads you might already know that we do a lot of track testing. From 2008-2015 we did most of our track testing at ECR, but that track has gotten too bumpy. For 2016-17 we have moved our road course testing to the 1.7 mile CCW course at Motorsport Ranch in Cresson, TX (MSR-C). I cannot exactly "baseline test" the 2007 Z06 chassis we bought, as it is in pieces, but I've got the next best thing.


Photo Gallery - Track Test, September 16, 2016: https://vorshlag.smugmug.com/Racing-...C-Test-091616/

On this beautiful Friday morning last September I was lucky enough to be able to drive three cars around MSR-C with an AiM SOLO lap timer and camera in each one. Same day, same track, same driver, similar tires. The first two included a 2013 Camaro 1LE that we modified (see this thread) and the same car owner's newly acquired 2017 Corvette Grand Sport 7-speed manual, which was bone stock and still sporting the dealer's paper tags. These were both owned by our tester Scottish Joe.



The Camaro was on fresh 305/30/19 Hankook RS-3 tires (on 19x11" wheels we spec'd) and the C7 GS was on fresh 285/335 Michelin Pilot Super Sport tires (factory equipped).



I also tested our accountant Jerry's almost bone stock 2012 "Centennial Edition" C6 Z06 Corvette, who has become a product tester for us on two cars now. The Z06 was on fresh 285/335 MPSS tires (same as what came factory equipped, same as the C7), plus it had better brake pads, some additional negative camber up front (-2.0), but it was also otherwise bone stock.



We got there early on a member day and the weather was great in the morning. I managed to get out on course in the Camaro when the course was devoid of traffic - which made for some easy laps where I clocked off some quick ones. This car was on coilovers, camber plates, 19x11" wheels, aftermarket headers, dyno tune, Cobra racing seats and Scroth 6-point harnesses. The Cobra racing seat and harnesses made driving the big 3800 pound Camaro effortless and I wasn't having to "hang on" like I did in the C6 Z06 - which had some of the worst stock seats I'd ever experienced.

Data Logged Track Videos at MSR-C in Vehicles on Street Tires:
https://youtu.be/6Rpepzil8FI - 1:21.89 in the stock 2017 C7 Grand Sport
https://youtu.be/athEpfLRH3o - 1:22.56 in the modded 2013 1LE Camaro
https://youtu.be/1_B2u_fOnww - 1:22.63 in the stock 2012 C6 Z06
https://youtu.be/fpWyzzf-pHk - 1:27.40 in a stock 2016 Focus RS
https://youtu.be/Cs6AF436ykE - 1:31.90 in a stock 2013 Scion FR-S

All three cars I drove that day put down fast track times but each was very different to drive. The Camaro had lots of track specific suspension/brake/power/seat/tire upgrades, so it wasn't exactly a fair fight there. All of these laps listed above were in street going vehicles using 200-300 treadwear street tires and the same AiM SOLO lap timer / data logger and driver. This AiM unit is within 0.1 sec of the AMB timing loop whenever I run NASA Time Trial events here, too.



The Camaro's stock 14.5" Brembo front brakes were upgraded with custom brake cooling that we made, G-LOC pads, and proper Motul fluid. These were absolutely infallible - watch the g-traces in the on-board videos and you can see how I abused them (1.1-1.2g stops on every corner, every lap) and yet never had a hint of fade. The Hankook tires worked great, generating 1.3g lateral in some places, mostly 1.1-1.2g. The brakes on the C6 Z06 and the C7 GS both had larger 6-piston iron brakes with GM's "half measure" semi-directed brake cooling, but both were actually pretty easy to overheat - after my fastest lap in the GS the brakes had massive fade. The brakes were more manageable in the C6 Z06, but that was mostly the pad upgrade - I could overheat them as well.


Left: The C7 GS brake cooling is a "scoop and flap" method. Right: The C6 Z06 has a plastic brake cooling duct

The C6 Z06 had Carbotech brake pads (XP10 front and XP8 rear compounds) and better fluid, so it was stopping better than the C7 GS. Other than the brake fade tendencies the $76K Grand Sport was GLORIOUS to drive and the fastest of the three that day. For stock seats the C7's upgrades "sport seats" were pretty good, but still left something to be improved upon. The stock brake pads were complete junk, though. Its hard to imagine how GM could deem these track worthy pads - I could completely fade them in only 2 hot laps on this brake friendly course.



I drove my fastest laps in the C6 Z06 and the C7 GS with a passenger riding shotgun (nobody would ride with me in the Camaro, ha!), and since I drove the C6 last it was in the hottest temps of the day (94F). It was still surprising that the C6 Z06 - my dream car - put in the slowest lap of the 3 cars I drove that day. Why? Well the stock suspension felt very soft and the car was rolling around like a school bus. The stock seats were downright awful - I felt like I'd slide up the door panel and pop out the side window on every big corner.

Both the C7 Grand Sport and C6 Z06 were on very fresh 285F/335R MPSS tires, so grip wasn't an issue. The C7 GS has different programming on the mag ride shocks and it seemed to corner MUCH flatter than the C6 Z06, which also had mag ride dampers. Again, the C6 Z06 was only 3/4 of a second slower than the C7 GS, but it definitely felt slower in the corners. Power it had for days, brakes were better as well. It was very interesting to drive these cars back to back in their stock forms.

continued below

Last edited by Fair!; 07-03-2018 at 06:25 PM.
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Unread 08-02-2017, 10:45 AM
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Default Re: Vorshlag C6 Corvette Development + Shop Z07 Race Car (Rampage)

OTHER C6 DEVELOPMENT

We have built some C6 parts and done track upgrades on these cars, which I will show in future installments of this development thread. Jerry's C6 Z06 has been going to the track 2-3 times a month for the last year so we get to see how pads, tires and such are wearing on his car.



Of course we weighed his 2012 C6 Z06, above. At 3217 pounds it is about the same as a base C6 Corvette, a touch heavier than the C5 Z06 (3050-3100 is common), yet hundreds of pounds lighter than Joe's C7 GS (below left, 3409) or the yellow C7 Z06 (below right, 3570) automatic we weighed. The C7 GS has a dry-sumped LT1 engine and iron brakes, with identical tire sizes, so its the closest C7 to the C6 Z06.



The C7 got a little bigger, a little more complex, and a good bit heavier than the C6 Z06. Its a bit funkier looking as well, at least to me. All C7 Corvettes have an aluminum frame and carbon fiber bodywork, too. The "non-Z06" C6 has a steel frame and fiberglass body, for what it's worth. My former 2005 C6 Z51 tipped the scales at 3150 pounds, with low fuel load, on a digital scale.

After that September 2016 track test I convinced Jerry to let us test out some better front brake cooling upgrades on his C6 Z06. This has helped extend his brake pad life on track significantly as well as reduce the chance of brake fade on track.



I will talk more about this C6 Z06 brake cooling kit when it is closer to production (we are testing version 2 now). Next time I will also show the Powerbrake 6-piston 350mm front brake upgrade kit we tested on Feras' 2008 C6 Z06, which he races in the Optima Ultimate Street Car series. I drove this car on track recently - which ruined me forever. Feeling how a heavily modded C6 Z06 handled on the same MSR-C surface was eye opening.



Feras' 2008 Z06 also just got a 7.7L stroker aluminum LS engine from our sister shop, Horsepower-Research. I will cover much more about the extensive list of upgrades on his Z06 next time.

VORSHLAG C6 Z06 - PROJECT RAMPAGE

So let's talk about this rolling heap of C6 Z06 parts I recently bought. This 2007 model Z06 was the innocent victim in an elaborate insurance fraud case and it ended up being confiscated. It was so mired in paperwork that the insurance company sent it to auction to be sold as parts.


Some Assembly Required

The damage to the actual chassis was minimal and it actually drove into the body shop I bought it from last year under its own power with every body panel intact. The title was a bit of a mess so it sat and sat, then parts started being "liberated" for use on other C6 Z06 body repairs. From the picture below left (taken 6 months earlier, when I first saw it) it lost the LS3 engine (part of the insurance scam - someone had swapped out the LS7), front fenders, right front inner apron, the hood, front nose, front bumper beam, driver's door, windshield, driver's seat, steering wheel, rear bumper cover, wheels, front upper control arms, rear toe link/tie rod, and both rear fenders. A lot of parts left this car...



It seems like there wasn't much left, and it would be nearly impossible to sell this to anyone who wanted to make a real street car out of this chassis. It didn't even roll. But I spotted it there when I bought another car from this same shop and told him to "Stop stealing parts off my C6!" Eventually I came back and bought what was left to make a race car out of...



I paid a little more than scrap value for this Z06, and honestly I am happy with the purchase. With 3 other race cars and a business to run, I couldn't have afforded to buy a $35-40K+ used C6 Z06 that was a complete car. And with what we have planned, it would be wasting a lot of good street parts. Brad and I fought with loading this car in 103F heat, first getting it onto dollies, then pushing it into my trailer (of course the winch decided to die that day), then we hauled it back to Vorshlag. The whole crew here helped unload it - and once again they thought I was nuts! But I had a vision, and managed to negotiate for a bunch of spare C6 parts the shop had. We filled the truck and trailer with random body parts they donated to the cause - a hood, apron, a door missing the window, some rear fenders, random wheels, and a few other bits.



Once we got it here Aaron got to work getting the rear hatch open. With that unlatched we found the rest of the entire interior, minus one seat and steering wheel. So we'll sell those bits soon to recoup some costs.



We didn't waste any time and the day after we unloaded the car I ordered a new pair of front control arms and rear toe link from the Chevrolet dealership, to replace missing items. Aaron spent 1.27 hours and installed those new suspension bits, bolted on the rear fenders and driver's door, then he installed on the Z06 front wheels and tires we got with the car. It rolls!



Of course I weighed these parts before they were installed. You expected anything less?? There are all sorts of weights we took of various C6 body parts, which I will show in future posts.



Brad got a weight of the Z06 assembled. This is with all of the body panels and hood we got with the car, the full interior (minus the seat/steering wheel), and the transaxle/torque tube... but no motor, nose, or front fenders. We're pulling interior parts out now and will show more of this build up next time.

WHAT'S NEXT?

I wanted to keep this first post short and sweet, and its already grown a bit long. We have already started getting our Z06 lighter by removing unnecessary engine bay wiring, plumbing and reservoirs.



We have also started removing interior and the bolt-on roof panel (below left) in preparation for roll cage layout. The first set of race wheels is being measured for and ordered soon, as one of the "freebie" wheels we got with the car isn't exactly holding air (below right).



I will show more of this shop Z06 race car build-up next time. We don't have a concrete build schedule or detailed plan for it yet so I will share that as it emerges. We have 3 other shop race cars and plenty of customer cars that all need attention, so our Z06 will get worked on as time and budget allows. I will also explain the project name next time, but Archer fans will have already figured it out. #Zima

Thanks for reading,
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Unread 08-02-2017, 11:49 AM
Mark-C Mark-C is offline
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Default Re: Vorshlag C6 Corvette Development + Shop Z07 Race Car (Rampage)

Hey don't forget the C5 autocross car in December doing a 1:22.5!!!
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Unread 01-18-2018, 10:18 PM
V-lag V-lag is offline
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Default Re: Vorshlag C6 Corvette Development + Shop Z07 Race Car (Rampage)

awesome build. Just wondering if you have new updates about the build?
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Unread 01-19-2018, 12:55 PM
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Default Re: Vorshlag C6 Corvette Development + Shop Z07 Race Car (Rampage)

Quote:
Originally Posted by V-lag View Post
awesome build. Just wondering if you have new updates about the build?


After a long search we found some OEM bodywork to replace what was missing on our C6Z chassis. The ZR1 front fenders and Grand Sport nose will be attached and fitted in the next 3 weeks, then I will make an update.
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Unread 05-15-2018, 01:34 AM
Delor Delor is offline
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Default Re: Vorshlag C6 Corvette Development + Shop C6 Z06 Race Car (Rampage)

Incredible write up and log of the build!
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Unread 07-09-2018, 05:50 PM
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Default Re: Vorshlag C6 Corvette Development + Shop C6 Z06 Race Car (Rampage)

Project Update for July 9th, 2018: It has been a while since I first posted about this C6Z shop build but we have been moving forward with this chassis. I'm buried in new shop construction but will take a moment to try to catch up on Project Rampage.

THE SEARCH FOR CARBON BODYWORK

A lot of what I share in our build threads is done to help you, our readers, from avoiding the mistakes I have made in the past 34 years of wrenching on cars. Often I need to re-learn the same lessons I have learned before. This was one of those times. Being Cheap is rarely the right call.



Remember - I bought this 2007 C6 as rolling chassis and it was missing a lot of parts: the engine, both front carbon fiber Z06 fenders, one of the front inner fender composite structures, the hood, and the rear fenders were off the car - among other things. The OEM front fenders on the C6 Z06 are the only real carbon fiber parts on the C6 Z06 (the ZR1 has these + a carbon targa roof panel). The rest of the car is straight up "fiberglass" composite, but the C6 versions of the Z06/ZR1/GS also have an aluminum hydroformed frame - a first for GM.


Not many OEM cars can fit a 335mm front or 345mm rear tire with properly sized wheels!

There are two distinct sets of bodywork for the C6 chassis: the base/convertible "narrow body" and the Z06, Grand Sport, and ZR1 "wide body". The differences in the wide body front and rear fenders (and front under structures) allow us to fit MUCH wider tires on these C6 models vs the the narrow body C6. Like these monster 18x12" front and 18x13" rear wheels are on our tester Jerry's C6 Z06 shown above. This car has stock fenders and swallows 335mm front and 345mm rear Hoosiers. We have sold lots of wheels for C6 widebodies in this size.


These are the fender mods needed for an E46 M3 to fit the 335F/345R tires!


We are able to fit these with no body work whatsoever. Do you realize how hard this wheel/tire setup is to fit to other cars???? The E46 M3 above has 62 hours of custom metal work to clear these same wheel/tire sizes.

OEM C6Z WIDEBODY FENDERS?

I went looking for C6 widebody OEM fenders the WEEK after I brought this car to Vorshlag in August 2017. What were the parameters of the fenders I sought out? Well first was strength. The OEM ZR1/Z06/GS "wide body" fenders are very light but also very fragile - racers and mechanics complain of how easy it is to crack these just leaning on them doing underhood work. And the way I drive they might take a few "off track" excursions. So I wanted something stronger than the fly weight stock front fenders.


The only real "carbon" on the C6 widebody are the front fenders. VERY light... maybe too light?

Next up was cost. Wow, the OEM carbon wide body fenders are PRICEY! They can cost $2000/each new and even $800-1000/each used (+ shipping), and most of the used stuff is damaged even at those prices. So I looked at aftermarket stuff....

FENDERS WIDER THAN OEM C6Z WIDEBODY?



These "super wide" front fenders by Supervettes seemed pretty slick. These come in all 3 C6 widebody variants: the Z06, the ZR1 and the Grand Sport, and each of these had unique fender vents. After talking to their composites guy he said most people buy the ZR1 version, the Z06 is rarely chosen and only one guy has ever bought the GS style. I had considered buying their extra-wide Z06 front fenders at $1900 in fiberglass or carbon at $2300, but just couldn't make myself do it.



I had seen these in person - these fiberglass ZR1 style Supervettes fenders on the C6 Z06 above belong to the owner at the body shop where I bought my rolling chassis - but the rears looked almost ridiculously wide. Maybe I was just being too picky and cheap? The fit was good but they do take some work to fit to the chassis, and they are a bit heavier. And since tires wider than 345mm rears don't really exist, what is the point? This option seemed more "stancey" than "racey".

LOW COST ZR1 CLONE FENDERS?



Next up I looked one of our vendors who makes composite fenders, hoods, and complete body kits. This company has multiple names: Extreme Dimensions, Carbon Creations, and Duraflex are the main three we have dealt with. We used their Duraflex (flexible fiberglass) nose on the widebody E46 M3, shown earlier.



They make "ZR1" style front fenders (above left) had a hybrid C7 / C6 front nose (above right) that looked like it might be cleaner aerodynamically than the Z06/GS/ZR1 nose (their OEM front noses are identical and are made for the widebody C6 OEM front fenders). Their website was unclear if this C7 "stingray" nose fit the wide or narrow front fenders.



After months of deliberations and searching for used OEM wide body C6 fenders to no avail, I broke down and bought their "carbon" front "ZR1 style" fenders and this C7 look "Stingray" nose. Again, their website was vague as to which C6 models these would fit - they claimed wider than stock and that they fit "all C6 models", but was that wider than C6 narrow body or wider than C6 GS/Z06/ZR1 widebody? I had several emails and calls with them before purchasing these fenders, the nose and a matching lower splitter section (to make the bottom flat so we could build a real splitter from there) shipped by freight truck to our shop.



I am the first one to tell you that some import composite parts will not always work like they claim, but I needed to re-learn this lesson again. These front fenders simply do not fit an OEM widebody C6 chassis. Turns out they were made for the base model "narrow body" C6 chassis/nose and just look like ZR1 fenders. We would have had to cut giant chunks of the wider inner structure off to make these narrow body / narrower fenders "fit" our widebody C6 chassis. No thanks.



And even if we had done this modification, these were nearly double the weight of the OEM carbon fenders and - more importantly - at least 2" narrower than real ZR1/Z06/GS fenders, per side. Luckily my emails up front to them made it very clear up front that we needed as wide or wider than ZR1/Z06 fenders, so they allowed me to return all of their bodywork for a refund, minus shipping both ways (about $330). I figured the $330 was the cost of learning this lesson. They said they would update their catalog, to remove any confusion for others in the future. As of this writing I still have not found a cheap widebody C6 ZR1/Z06 front fender.


This Duraflex 6 piece flare kit for the 86 chassis is about $400 and easily covers an 11" wide wheel

Now I don't want to disparage this company (Extreme Dimensions / Carbon Creations / Duraflex) because their products to have a place in racing / car builds, and they have a MASSIVE catalog. Like I showed earlier, we used their 1M nose on an E46 M3, and I have recently purchased the Duraflex 86/FR-S/BRZ flare shown above for use on our shop 2013 FR-S. These bolt-on flares should easily cover the 18x11" wheels we have coming for this car, which should work well with 315mm tires and V8 power.

BACK TO FINDING OEM C6 WIDEBODY FRONT FENDERS?



After nearly 6 more months of searches, I came upon these used black OEM C6 ZR1 front fenders, shown above. They looked nearly perfect and the price was right (still cost 4 figures).



I also managed to score a free nose from a C6 Grand Sport - which needed some repairs but was easily fixed - from my painter friend Shiloh. With as tight as my budget was at the beginning of 2018 (in the middle of building a new shop, upcoming move, expanding our CNC machines), this was exactly what I needed.

LET'S SEE IF WE CAN HAVE SOME CARBON ZR1 WIDEBODY FENDERS MADE!

I was still worried about damaging these fragile, expensive OEM carbon front fenders on track, so I made a deal at the 2017 PRI show to send our C6Z chassis - with OEM bodywork attached - to a manufacturer who makes real carbon fiber parts, at affordable prices.



The deal was they would use our car to make molds for replacement front fenders, rear fenders, and doors (maybe some other bits) in carbon fiber, made for racing use - similar weights as the OEM rear fenders, lighter than stock doors, and as close in weight as the carbon fronts - plus stronger and more cost effective. This way, if I stuff the car into a tire wall I'm not out one hojillion dollars for new OEM bodywork!



Now i needed to get all of the OEM bits ordered and installed onto our rolling chassis, then arrange for transport to the west coast...

ORDERING OEM PARTS + ASSEMBLY

As I started in a previous post, I bought this 2007 Z06 chassis as a rolling chassis, partially disassembled. The body shop I bought it from took a complete car and started picking parts off to use to fix wrecked C6 Z06 cars that had rebuilt / salvage titles. Our car had a "parts only" title, due to a paperwork issue with an insurance claim, so it was impossible to sell to be used for street use. For a race car, however, its perfect.



They had taken the right front inner fender structure off of this car - which is a fiberglass piece normally bonded to the frame. It is a LOT of work to remove cleanly, and even more work to reinstall with the factory thick epoxy goo for a repair to another chassis. Essentially if you damage this piece in a crash, you should buy a new one from GM, remove the old one, bond in the new one with a 24-hour set epoxy, and temporarily install the rest of the bodywork to line it up right.



Well we got another widebody C6 removed structure from this car with the purchase - why they removed it is anyone's guess. Instead of bonding it to the aluminum chassis I decided to have it bolt on, which will make it easier to perform some of the underhood fab work we have planned. The C4 Corvette chassis (above) had a more accessible engine bay due to the large (and heavy) clam shell hood/upper fender sections, and bolting this inner section on will give us similar room on the C6 - albeit without the ease of just opening the hood.



It looks like whoever tried to remove the bonded inner fiberglass structure from this car damaged it pretty badly (see above) - there are big chunks of fiberglass still stuck to this frame. Those areas had to be sanded away before we could install the used OEM "widebody" inner structure we got onto this chassis.



Brad used a heat gun and some scrapers to loosen the epoxy goo and removed all traces of it from the aluminum frame rail. It took some patience and elbow grease, but eventually it was all removed - as well as the fiberglass fragments. With the aluminum frame rails now bare, we could attach the replacement inner.



We began by acquiring a gaggle of OEM parts to get this car put back together externally, to then ship the car to Anderson Composites in the first part of 2018 for molds. We lined up the fender liners, some front bumper cover support parts, the front bumper cover from a C6 Grand Sport, and the ZR1 fenders mentioned above.



Brad began fitting the right front inner fender support in late January - after we ordered some M8 nutsert parts and tools for some of the inaccessible parts of the frame. Some of the bolts we used to attach this inner were into "blind" areas, and some were thru-bolts, as shown above.



Bolting these inners on instead of bonding lets us shim them to fit perfectly, to get the fender gaps right.

continued below

Last edited by Fair!; 07-10-2018 at 08:25 AM.
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Default Re: Vorshlag C6 Corvette Development + Shop C6 Z06 Race Car (Rampage)

continued from above

These are the M8 nutserts - threaded inserts that install like a blind rivet - which we used to install the inner fender structures in some hidden locations. As you can see below, the factory used these in the same size in the bottom of the frame rails.



The ends of these boxed, hydro-formed frame rails are usually capped off and inaccessible on the inside, so bolts & nuts are not an option down in here.



On the exposed upper flanges of the frame rail (see above left) we used thru-bolts with nuts on the back side. With the additional holes drilled into the frame and inner structure bolted down the inner and fender were shimmed and fitted, so that the fender lined up with the door. We can unbolt this fender and the inner structure now in about 15 minutes for "deep access" to the engine bay, at least on this right side.



Once that right side fender was installed, the left front went on and lined up somewhat easily. Now it was time for the hood - which we got with the chassis purchase, from a red C6 - but first, we had to source stock hood hinges and repair the studs those bolt to at the frame.



These new OEM hinges above were able to bolt up to the two studs sitting on top of the frame rails after some minor repair. Whoever chopped the ends of the rails off left just enough meat in there to keep the studs, and one bent one was later reinforced and welded (see the "capped end" work below).



With the hinges loosely assembled to the frame rails, the hood was then installed. Then the hood and fenders could be adjusted to line up together and up against the front edge of both doors. We removed the factory hood latches and cable release at the firewall (heavy) and will instead use a pair of AeroCatch latches when we pick the final hood (won't be this red one).



Next up Ryan made a small aluminum support panel for the underside of the tear in the Grand Sport widebody front nose. This bumper cover included some of the OEM structural bits, so it was easier to line up the tear than a bare bumper cover itself. He bonded the small support panel to the underside of the flexible cover with epoxy and let it set up overnight.



The front section of the frame rails had been hacked off to repair another car - so instead of robbing another chassis of these ends ($$$) and painfully lining those up, I decided to just make a crash bar from aluminum tubing. I asked Ryan to clean up the cut-off ends of the aluminum frame rails, to square them up and make the ends symmetrical, side to side. He then made some flat plate sections to cap off the rails and TIG welded those to the cut frame ends. We will come back and bolt a tubular aluminum front crash bar to these sections later.



We sourced the crash bar tubing in 6061-T6 aluminum (above left) but we were tight on time (my shop cars pay the company $0/hour!) and Ryan had already lined up the nose structure to a bunch of additional brackets we sourced from GM (above right). So he was able to line up the front nose to the chassis without the crash beam in place (which we will definitely add later).



Next up a pair of used C6 headlights I sourced from eBay were installed. I looked for new units but they are 4 figures each - no cost effective knock-offs exist yet. These OEM units were $400 for the pair, which is unusually cheap for a complete set of even used C6 lights - but unlike the pictures online, these were all full of sand (?!) and had scratched lenses when they arrived. I should have known that the "unbelievably low price" meant they looked nothing like the pictures in the ad. What can I say - "typical eBay purchase". The nose was installed finally and everything lined up together.

TEMPORARY STEERING COLUMN

The stock steering column was removed (and the steering wheel was missing) when the interior was stripped. But soon we will need to steer this car on and off a trailer, for transport while the bodywork is being made. We have an electric assist column in the plans long term but we needed something - now.



I asked our crew to build this temporary steering column, shown above. In hindsight we could have just reinstalled the OEM steering column and just bought a steering wheel and hub adapter, but I wasn't ready to pick the steering wheel just yet, and the GM hub adapter wouldn't be re-used, so instead I bought $60 worth of parts above. It looks terrible, but will be tossed out when we make a proper racing column for the car later (just an OEM to 6-bolt hub adapter is $90 + a $250 steering wheel = this was cheaper for temp use).

LOTS OF OEM LIGHTS/GRILLS/SILLY BITS

After getting the car looking mostly complete, the guys at Anderson wanted to see more of the OEM bits if they were going to make a replacement nose in carbon. So I spent a couple of months chasing down all sorts of grill inserts, fog lights, turn signal / side lights, and more.



Valuable lesson learned here. So I did find knock-off fog lights, which are apparently damaged often enough to support this line of cheaper offerings. And the base C6 vs the widebody C6 look very different, yet all of the online offerings show the same part number. The parts above arrived and they look "wrong", so I paid to send them back and then bought OEM replacements from GM for 3x the cost.



Joke is on me - turns out the same foglight fits both the base and widebody C6 noses, even though the foglight openings are wildly different in shape. The larger "base" foglight shape is covered up by the widebody nose's opening. There is a carrier on the inside of the bumper cover the matches up perfectly to the weirdly shaped foglight. I never even thought to check the cheaper ones I bought online. Oh well, now I know. And no, these will likely never be used on our car in racing trim - just got these bits for Anderson to verify molds if they make the carbon nose replacement.



These side marker lights mount to the nose and I found knock-offs for the OEM parts, which I ordered. Annnnd that order was cancelled, due to lack of stock. So I sourced these from GM for 2x the cost. Another piece likely never to see racing use, just need for Anderson's checks if they make the nose.



Brad and I both spent some time with the heat gun, solvents and an eraser wheel on a drill removing some dried adhesive that was baked onto the paint. This was from clear adhesive backed film that was used to cover the open windows (which were there but the battery had been removed) and gaping maw of the missing windshield. This caked on stuff was a real pain to remove, but the eraser wheel worked the best - after the car was left outside in the sun to soften the dried adhesive. Cleaned up and ready to transport to California in late March!



We fought for two months with transport companies and in late May we finally found one that would 1) transport a non-running car, 2) would transport a car without a windshield (enclosed transports only), and 3) that actually showed up! Now the truck that arrived was an enclosed ramp truck had no winch, so it took 8 people to push it up the steep ramp into the truck. At least it steered and the e-brake worked. Anderson has the car now and should hopefully have it wrapped up and ready to transport back to us in July or August?

TERMS OF RAMPAGEMENT

It was a lot of months chasing down parts and re-assembling this car, but it was finally shipped out just before we moved our shop. But this car needed a name before it left...

Those of you who are not fans of the hit animated series ARCHER might be wondering why the hell are we calling this car "Rampage"?? First, go back and read the build thread for our C4 Corvette, Project Dangerzone. Notice the Archer themed jokes? If you don't watch Archer you are missing out on a lot of one liners.



In Archer season 2 episode 9 called "Placebo Effect", Archer gets cancer. When he discovers the chemotherapy drugs he's been taking for his breast cancer are counterfeit (sugar pills and Zima), he sets out to destroy the Irish Mob criminals behind the scheme. He goes on a "Rampage", killing everyone involved with the fake chemo drug ring... so pretty much how driving this Corvette will be like, right?



Expect to see ZIMA sponsorships (a tasty 1990s malt beverage), breast cancer awareness decals (legit), some taunts to the Irish, of course a few other Archer series nods on this car when it hits the track.



We transferred the "RAMPAGE" rear plate from the DangerZone C4 over to the C6Z. Along with adding a new the C6 OEM bumper cover (shown above) and some structural bits needed to mount it - all of which I bought from GM. Hoping that Anderson will also turn this rear cover into a carbon piece, but I doubt it. I'll be happy with all 4 fenders and both doors being carbon - anything else is a bonus. These parts are slated for production so everyone can buy them, once they are ready.

WHAT'S NEXT?

We are busy working on a number of other shop projects and lots of customer builds, of course. The shop move is done but construction continues, so I am kind of glad the C6 is at Anderson for another month or so.



Since starting on this C6Z we have painted, finished and sold my BMW E46 330 "daily driven track car" experiment (above left), so we were left with nothing to race. So in late February 2018 we bought this red 2018 Mustang GT (above right) and have already done two rounds of mods, lots of track testing, raced it in NASA and SCCA Time Trial events as well as an Optima series event. There are build threads for both of these on the Vorshlag forum, linked in this paragraph.



Meanwhile HorsePower-Research has been building these tall deck aluminum block 527" LS7 engines in ever crazier versions. Its the biggest LS engine in the world, at 8.6 liters! The 1/2" taller deck height on the RHS aluminum block is hard to even see unless you know what to look for. So we are thinking about using one of these for our C6 here. You can read more about some of the street car versions of this 527 that made 720 whp on E85 at this link. With some more advanced heads, a custom intake manifold, more compression (race fuel) and a conservative 8000 rpm power peak, it could sneak up on "four digit power". So... pretty much a Rampage.

More soon,
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