Many of us went through a Corvette phase in our younger years. I certainly did, but I was never as smitten with them as my peers or my dad was. And that was despite the Vette’s seriously vivid color palette and raucous exhausts. Perhaps I was too deep in the cult of the R35-generation Nissan GT-R at the time, but only one Corvette still makes my heart skip a beat, thanks to its race-car-like widebody and monstrous big-bore engine: the Pratt & Miller C6RS.
Who the heck is Pratt & Miller?
If the C6RS looked like a race car, that’s because it boasts a connection to one of the Bow Tie brand’s most zealous motorsport partners—Pratt & Miller. No, not the outfit known for making F-22 Raptor engines—that’s Pratt & Whitney—but the notion of a stealth fighter is fitting when it comes to the brutal sixth-generation Corvette in question.
Founded in 1989 by Gary Pratt and Jim Miller, Pratt Miller is an engineering firm within the Oshkosh Corporation—the masterminds behind an armada of heavy machinery, including garbage trucks, fire engines, military transport trucks, and even that weird new USPS mail van. (While they’re now known as Pratt Miller Engineering or just Pratt Miller, for the purposes of this story, we’ll reference them as Pratt & Miller, the name they went by when they created this Vette.) Under Oshkosh since 2020, Pratt Miller lends its expertise and services to military vehicles, modern mobility solutions, and, most prominently, motorsports.
Since its inception, the company’s main quest has been to succeed in the crucible of racing. With the C5-R, the outfit became the official provider for the Corvette Racing Program’s 1999 season. The company has since competed in IMSA, Le Mans, IndyCar, and NASCAR. Pratt Miller’s talents encompass software development, race team support, and full, ground-up race car engineering. Currently, Pratt Miller operates a factory-supported team of to Corvette Z06 GT3.Rs in IMSA endurance racing.
C6RS: Why a Road Car?
The team’s work with the Corvette Racing Program undoubtedly paid off. By the mid-to-late 2000s, GM amassed dozens of victories spread across IMSA and endurance battles at Le Mans and Daytona, all with sports cars adorned in a now-iconic yellow-and-black livery. Arguably most impressive of these wins was the Corvette’s one-two victory in the 2005 24 Hours of Le Mans GT1 category, well ahead of rivals at Aston Martin and Ferrari.
Pratt & Miller saw it fit to celebrate its victories with—pardon the cliché—a “race car for the road.” We’ve all heard that claim touted again and again in a MotorWeek Retro Review or written publication, but Pratt & Miller took the brief seriously. If it was going to put its name on special-edition tuner Corvette, it had to befit the company name. Rather than a run-of-the-mill special doomed to linger at car shows with only an exhaust, some glitzy stripes, and a numbered plaque to set it apart, the project had to be true to the Pratt & Miller C5-R and C6.R race cars it sought to honor.
Pratt & Miller’s 8.2-liter Thriller
Enter the 2008 C6RS, which first reared its head at the SEMA show in 2007. Pratt Miller started with a standard-issue C6-generation Corvette Z06, itself a 7.0-liter, 505-horsepower giant slayer. They then chopped it a bit, stretched it out, and dropped in a massive, billet aluminum-block engine with LS7 heads that would make any Viper V-10 owner sweat.
“The C6RS is what a Corvette can become when not restricted by the requirements of assembly-line-based manufacturing,” said Pratt & Miller spokesman Brandon Widmer in 2008.
GM engine specialist Katech Engines replaced the stock 7.0-liter LS7 with an 8.2-liter V-8 tuned on E85 Flex Fuel and utilizing a 4.205-inch bore and a 4.5-inch stroke. That configuration put this engine a hair over 500 cubic inches. For reference, the 2006 Dodge Viper’s V-10 was only a smidge more voluminous at 8.3 liters. The Katech engine’s compression ratio of 11:1 remained unchanged from the LS7’s.
Katech’s creation belched 600 horsepower and 600 pound-feet from unique oval-shaped Corsa exhausts, evocative of Satan practicing his Rob Zombie impression through a megaphone down an empty tunnel. No blower or snail in sight here—just old-school, free-breathing genius bolted to a tried-and-true Tremec T-56 manual transmission blueprinted by Pratt & Miller itself. For reference, GM’s own Corvette ZR1 from 2009 wielded a supercharged 6.2-liter LS9 to generate 638 horsepower and 604 pound-feet. And despite the C6RS motor’s monster displacement and stroke, the redline was respectably high at 7000 rpm.
(Interestingly, there is one C6RS running around with a modified LS9 pushing 756 horsepower. It served as Gary Pratt’s one-time personal car, and has bounced around a couple of auctions in the last few years, with both Mecum and Gooding & Company. Bodywork and handling components remained largely the same.)
The car’s signature widebody was a carbon-fiber caricature of the C6.R race car’s outfit, adding 1.5 inches to the width of a stock C6 Z06. While it lacked the race car’s massive GT wing, the C6RS made up for it with a tastefully discrete active spoiler that retracted into the rear decklid. The front nostril expanded for the Katech V-8’s ram air intake, and the heavily vented fenders were flared at all four corners to clear the 295-front and 345-rear Michelin Pilot Sport tires. The rolls of rubberized super glue enveloped 18-inch front and 19-inch rear centerlock BBS wheels, because why should Porsche GT cars get to have all the centerlocks? There was also a handy front-end lift that could raise the nose to clear obstacles or lower it for a more aggressive stance.
Along with 80 pounds of Dynamat sound insulation, Pratt & Miller shoehorned bespoke leather seats with much-improved bolstering and custom two-tone upholstery into the interior. Perhaps the company felt the stock C6 seats were as supportive as a lawn chair, or maybe it was just to match the grip from the humongous Michelins and the revised, 1.5-inch-lower, height-adjustable suspension. Brake cooling ducts chilled the six-piston front Brembos clamping down on 14-inch rotors, which, paired with the four-piston rear brakes, reined in this 202-mph supercar fighter.
At $187,500, which equates to roughly $273,000 today, the C6RS was also priced like a supercar fighter. And that price did not include the donor C6 Z06 or any optional extras, such as interior accoutrements. Pratt & Miller’s benchmark was to match or surpass European supercars of the time, but imagine taking close-to-Gallardo cash and dumping it from a bag onto the hood of a Chevrolet still saddled with leaf springs—carbon body or not. Yowza.
C6RS: Walking the Walk
Initial reactions from journalists who drove the C6RS indicated they were head over heels. Some might have even foamed at the mouth a little. That shouldn’t be shocking, given that, on paper, the C6RS could hardly have been anything other than a hellacious riot of horsepower, noise, and handling prowess.
“The C6RS feels just as at home going 140 mph as it does 30 mph,” Motor Trend writer Scott Parker effused about the car’s composure, in spite of the base Corvette’s relatively antiquated suspension design. Even on the slightly bumpy 2.1-mile Autobahn course, the C6RS still rode like a Cadillac.”
“That tremendous torque demands judicious use of the throttle as the car catapults from one corner to the next,” exclaimed Motorweek presenter John Davis. “Driving the C6RS at these speeds borders on sensory overload!”
TheSmokingTire podcast host and current Road & Track Editor-at-Large Matt Farah praised the car’s otherworldly engine and revamped interior but reminded audiences of its steep price. He was easily the most critical of it:
“So, if you’re looking for the performance bargain that is most Corvettes, I assure you, you will not find it here,” Farah stated. “But whereas most Corvettes are fast cars–powerful cars, fun to drive–they are not supercars.” Even in the wake of that tear-jerking price, however, he couldn’t deny the fun factor that compelled seven eclectic customers to drop that kind of moolah on a hopped-up Chevy. “Yeah, it’s got a few miles on it, but as you can see, more than enough to put a smile on this guy’s face.”
The price was easily the biggest bone to pick, especially when a new ZR1 was about a third of the all-in price. However, that Katech V-8, shockingly capable chassis, livable interior, and drool-worthy race car cosplay was enough to win the wallets of seven paying customers. In the end, that was quite a bit fewer than Pratt & Miller’s planned 25-car run.
Remembering the C6RS
One could argue that Pratt & Miller cemented the C6RS’s reputation as one of the more impressive high-performance special editions, even if it wasn’t as stripped-down as something like the original 1960s Shelby GT350 or the Viper GT2 Championship Edition of the late 1990s.
As revealed in a 2013 press release from Pratt Miller Engineering, the C6RS that debuted at SEMA ultimately went to Jay Leno’s orphanage for wayward collectibles, four made their way into private hands, and two were claimed by Pratt & Miller themselves. Where they are now is anyone’s guess, but a few have traded hands over the years for serious coin.
In 2022, Hagerty reported on an example that sold via Bring a Trailer for $366,000. Corvette Magazine recently posted a classified listing for one trying to fetch a cool $375,000. In modern terms that’s into 296 GTB or DBS Superleggera territory. But while its present-day values will easily make supercar owners wince at the thought of that much coin for a 16-year-old C6, the driving experience sheer and collectibility hold allure for Corvette obsessives.
King of Corvettes
It’s nice to know that the Pratt & Miller Corvette C6RS wasn’t just some send-off for a now-forgotten tuner that became lost to time and withered into obscurity. Quite the opposite, actually. To this day, the engineering firm remains a devout supporter of GM’s motorsports efforts, helping propel its Corvette team into its 25th year of taking the fight to the Blue Oval and the Europeans with the Corvette C8.R race car, which is currently fielded in today’s IMSA GTD Pro and World Endurance Championship LM GTE categories.
Not bad. Call it the perks of suckling from the same corporate Wisconsin mama that nurtures war machines and mail vans.
As for ye olde C6RS, that homage to motorsports ingenuity will forever be a forbidden fruit by virtue of its legacy and scarcity. Haters can hate on it like it’s just some prettied-up C6, but this is far from what anyone’s uncle can build in their garage with enough money and Pabst Blue Ribbon. It’s a testament to the successes of one of GM’s most loyal companions and a tribute to an era of modification where there truly was no replacement for displacement.
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