This thread is now merged from three different C5 & C6 Corvette development threads. There was so much cross-over among these 3 threads that it became easier to merge them and update them all here. Sorry for any confusion!
Project Introduction - March 26th, 2021: We just bought a 2006 Corvette for Amy to use to at autocross, on track, and on the street. This will be a rules-free build that will be done on a "normal" budget, with an emphasis on both streetability and great on-track manners. While this car might see some use in autocross or time trial, it will NOT be built strictly for those purposes or around any given rule set. Just a "fun buggy" that serves as a back-up car for when our main race cars are down that can actually be driven to events.
And here it is in all of its 16 year old, used car glory! This is a "narrow body" base model C6, with a 6-speed manual and 45K miles that we bought for $20K. It is bone stock and overall in 98% perfect shape mechanically and about 95% perfect visually. A squeak under hood, a few scratches, and the wheels have some road rash - all things that are easy to fix/replace with parts we had planned.
Now many of you reading this are likely wondering - why wouldn't we buy a widebody Z06 or Grans Sport if you wanted to get a C6 Corvette for performance use?!? It came down to two things: First was cost. I looked at comparable mileage C6 Grand Sports were more than double ($43K+) and low mileage C6 Z06 cars were higher still ($50K+). I found only higher mileage (usually 120K+) narrow body C6 cars for the same or more costs, and 100% of those were automatics (yuck). It was an easy purchase that we could get on track immediately.
Second was: low stress. This C6 being a less desirable "narrow body" means we won't be as inclined to "go crazy" and build some wild race car (plus I already have an all carbon widebody C6 Z06 in storage, waiting for a complete build, above). As a relatively low value C6 we won't stress out if it gets a scratch or a tiny bit of cosmetic damage. I try to explain further why we went this route below...
HISTORY, MODEST GOALS & BUDGET
Vorshlag started out 16 years ago developing parts for the most flawed cars, and our unofficial motto was "We make your car SUCK LESS." The more terrible the OEM suspension, the more improvement we could offer! Most sporty car models then (as now) were built with McPherson strut suspensions, soft spring rates, inadequate roll stiffness, skinny wheels and tires, and all sorts of other performance compromises.
This is where we started.... strut suspension cars
We started out with BMWs and Subarus as the primary targets of our parts development, and that method of attacking the "low hanging fruit" has paid off for the business. I am glad we went that direction, instead of chasing true sports cars that came with MUCH better stock suspension options. And in extreme cases we even swapped in LS engines, which I first stared doing in 2002.
Cars with terrible suspension are easy to make big improvements on!
But the year before we started Vorshlag (2004), Amy walked into a GM dealership to look at the then brand new C6 Corvette. This was just days after the new generation Corvette hit the streets, and it was a radical departure from the C5 generation before it (which neither of us liked, since the C5 is the Corvette with Four Asses). She saw a new C6, fell in love, and custom ordered a 2005 Corvette Z51 6-speed in silver. It arrived a few weeks later. It came from the factory with decently wide wheels, world class suspension, and LS2 power - with a 186 mph top speed in stock form.
This was our 2005 C6 Corvette Z51 - which we ordered new in 2004
This was her first new car purchase and it was just an amazing car, which she loved. We both autocrossed it a few times (after several years away from that sport) but mostly she drove it to work and loved every minute of it. I hooned it a bit... took it to Houston Raceway Park and ran the 1/4 mile (12.8@112), weighed it on a scale, dyno'd it (355 whp). The wheel offsets needed proved to be a challenge so I bought some 17x11" C4 ZR1 rears and we ran 315/35/17 Hoosiers, which poked like crazy!
We sold our 2005 Z51 to help pay for a new home + shop, to concentrate on starting Vorshlag in 2005
But in 2005 when we had just started Vorshlag and had some tough choices to make. Keep a relatively expensive new car / note ($45K) while building an expensive new home with giant attached shop (which we ran Vorshlag out of from 2006-11)? A car we would have trouble applying our Vorshlag fixes to? It did not help the business, and it was a tough choice, but we sold it after 1 year - to a dealer, who paid us sticker price - because NOBODY could get C6 models at the time, and our rare Z51 6-speed no option car was SUPER rare at the time (90% of early C6 models are automatics).
My main track car (S550 Mustang) was sold. Amy's FR-S is being LS swapped and stuck behind customer cars
Fast forward 15 years, and after many years of having multiple track and autocross capable cars at any given time, 2020 was a bleak year for racing in the Fair household. We sold my 2018 Mustang (above left) in August 2019 to move onto a more serious S550 race car build, but that stalled out with manpower limitations in our shop and a customer car build backlog. Likewise Amy's 2013 FR-S (above right) was pulled from racing duty in late 2018, but the LS swap work on that car stalled out for the same reasons. So Amy and I haven't raced anywhere in our own cars going on two years! Neither of us like borrowing cars either. We're both going stir crazy NOT competing track or autocross events.
I have been bumming co-drives for a year in a friend's C5 we used for development
At an event at Eagles Canyon Raceway a week ago (above), Amy was lamenting our "stalled out" race car builds and declared - "It is time to buy another car, that runs, that I can race RIGHT MEOW." We puzzled over a few ideas while in the drivers lounge with some friends, and Jason here at Vorshlag mentioned this 2006 Corvette he had for sale... Yadda, yadda, yadda.... she bought it!
Of course, every car we buy for the business has to "earn its keep" here at Vorshlag. 16 years after starting Vorshlag and we are indeed developing parts for more than just "Crappy McStrut" suspension cars. We have even had some success with our products developed for the C5 platform, among other non-strut cars.
For this narrow body C6 have a small budget for this one, and overall build will be fairly mild - we want to keep this a 100% street legal, nice driving car *that is also track capable* and quick. Goals do NOT include TT track records or some SCCA obscure autocross class rules - just an all around "fun buggy" that she can run "where it fits".
While Vorshlag is not known as a "Corvette Shop", we still make a number of unique parts for some Corvette models and have worked on a number of C4, C5, C6, and C7 Corvettes over the years (and I have personally owned 5 Corvettes - two C4s and three C6s). For this narrow body C6 there are a number of areas we can improve with our part solutions - which we will prove with track testing, data, and product development.
Initial plans for this car include the usual Vorshlag upgrades: custom wheels and wide 200TW tires, MCS non-remote coilovers, G-LOC pads on fresh Z51 rotors, adjustable swaybars, maybe seats, and of course a number of new C6 specific "track products" from Vorshlag. We will share the development of the car and these parts in this forum build thread, of course.
I have driven numerous C4, C5, C6 and C7 Corvettes at Motorsport Ranch on their 1.7 mile CCW course
Will get a baseline lap in stock form at two race tracks: MSR Cresson and/or ECR. Having driven 500+ laps at MSR in dozens of cars and 1000 laps at ECR (on the old 2.9 mile layout), with dozens of wins and class track records in Time Trial at both locals, these tracks will be best suited for our initial and continued testing on this C6.
Baseline laps will be done with just with fresh Motul RBF600 brake fluid and stainless brake lines (which the C6 already has). We will go back after each major round of parts changes to chronicle any lap time gains or losses. To help with this testing we purchased a membership at Motorsport Ranch and a membership at Eagles Canyon is coming shortly.
FIRST INSPECTION & WEIGHING
On March 25th, 2021 we put the new C6 on the lift for the first time to take a look at the car more closely. Brad wiggled all of the bushings, wheel bearings, noted any leaks or issues. First things we noticed that needed replacement: idler tensioner pulley, engine mounts, oil pan has a slight leak, hood lift struts were shot, and I wanted to do a full oil & filter replacement. We will also swap in fresh plugs (NGK TR6), plug wires (Taylor 10mm), and plug wire heat boots (DEI).
We also, of course, got an initial weight. And it was a pleasant surprise, and a relief after dealing with 3600 pound pony cars for the last fee years.
Ideally I like to weigh a car with the fuel tank as empty as possible. This makes it is easier to compare car-to-car weights. Why empty and not full? Because we almost NEVER autocross or track a car on a full tank, but have done those events with low fuel levels (There is no such thing as "good ballast weight"). We run the least amount of fuel needed for the session and/or to prevent fuel starvation. But this one had 5/8ths of a tank when we bought it, and we didn't have a lift clear for very long so we took the weight we could get.
Now my memory of our 2005 Z51's weight was 3148 lbs, which I weighed at a drag strip in 2005 - but that was 16+ years ago, before we really started Vorshlag, before we owned our own digital scales, and before I began documenting EVERY weight on EVERY car we owned or worked on. Plus, that 2005 Z51 had bigger brakes and wheels than this 2006 "base" car, so maybe that makes up for some of the weight difference? Or maybe my memory isn't 100%...
continued below
Leave a comment: