The Ultimate C6 Corvette Was Not the ZR1….
…It was the Pratt & Miller custom-built sixth-generation Corvette C6RS with a massive 8.2-Liter V8 engine under its hood!
In 2006, the company behind the Corvette C6.R pulled out all the stops and developed a Corvette (based on a Z06 donor car and a lot of amazing engineering) that featured an unprecedented amount of horsepower and torque under its hood while packing ultimate luxury inside its ultra-wide carbon-fiber body. The car, which was revealed at the SEMA show in 2007, was called the C6RS Corvette.
“The C6RS is what a Corvette can become when not restricted by the requirements of assembly-line-based manufacturing,” says spokesman Brandon Widmer of Pratt & Miller Engineering and Fabrication, the company that GM had partnered with to build its immensely successful C5.S and C6.R race cars.
Pratt & Miller Engineering, who has been a long-time partner with Chevrolet and is the “heartbeat” of the Corvette Racing program, is the company that gave General Motors eight class wins at Le Mans, three with IMSA, eleven at the 12 Hours of Sebring and three at the 24 Hours of Daytona, to say nothing of the numerous victories at (now defunct) race events like those that made up the American Le Mans Series and the Pirelli World Challenge.
In 2006, Pratt & Miller had developed the GT1 variant of the 2006 Corvette C6.R race car. In it, the team introduced a 7.0-liter LS7.R V8 engine. Much of the decision process behind engine size in the race car was based on regulations and class requirements of the American Le Mans Series. About the same time that Pratt & Miller had begun fabrication of the C6.R, Chevrolet approached the racing team with the idea to build an exclusive road-ready version of the C6.R – one that would feature the performance of the race car while being legal to operate on the open road.
Pratt & Miller was only too happy to oblige!
“With the C6RS, we analyzed every major component of the production Corvette, looking for opportunities to optimize design for performance, durability, quality, and aesthetics,” says Widmer.
Recognizing the importance of the powerplant, Pratt & Miller installed a K-tech aluminum block, naturally-aspirated 8.2-liter V8 engine under the hood of their “ultimate” Corvette. The engine, which had been manufactured by Katech, was a monstrous 5oo cubic inches and produced a robust 600 horsepower and 650 pound-feet of torque! While it’s true that the 2009 “Blue Devil” ZR1 would ultimately produce more horsepower (638HP out of its LS9 engine), the torque output of the C6RS was 46 lb/ft greater than that of the ZR1. More impressive still, the engine was designed to run on E85 fuel.
The LS7.R V8 engine was paired to a Tremec T56 manual transmission that been specially blueprinted by the Pratt & Miller team to provide the smoothest shifts possible while also being capable of enduring the monstrous horsepower being generated by the engine.
While there’s little argument that the powerplant was the defining characteristic of the C6RS Corvette, it was by no means the only distinguishing characteristic of this exclusive automobile.
The exterior of the car featured custom carbon-fiber bodywork with fully functional aerodynamics. It included a widebody conversion with integrated brake ducts and ram-air intake, Pratt & Miller’s C6.R “waterfall” hood and louvered fenders, and Arvin Meritor’s Dynamic Ride Control suspension including a nose lift system.
The original Z06 chassis was also overhauled. To better recreate the drivability of the race car, Pratt & Miller introduced a computer-controlled suspension system that lowered the car by approximately 1.5 inches from its stock ride height. To account for daily road conditions (such as curbs), the car’s body can be quickly raised and lowered. Elsewhere, Brembo brakes featuring monoblock calipers were installed to provide the massive braking power needed to quickly slow/stop the C6RS. Given its straight-line acceleration capabilities, this seemed the only obvious choice. Those Brembo brakes were encased behind a set of custom BBS center-lock wheels (again, not unlike the wheels used on the C6.R race car.) The front wheels measured 18×11 inches while the rears were a massive 19×13.6 inches.
While the car’s performance capabilities were undeniable, Pratt & Miller also recognized that the car needed to offer potential consumers the luxuries associated with purchasing a road car. The design group at Pratt & Miller had never been satisfied with the factory fit, finish and overall material quality used by GM when manufacturing the standard Corvette’s cockpit. Recognizing an opportunity to improve upon the offerings, they enlisted the help of Shelby Trim to bring the interior up to the standard they expected. More than 160 man-hours went into the reworking of the car’s interior, but when they were done with it, there was no question that they’d achieved something special. The C6RS interior now featured some of the finest quality hand-stitched leather ever installed in a Corvette, including a leather-wrapped roll bar. They also installed a pair of aggressively bolstered sport seats and a flat-bottom steering wheel. Lastly, to provide drivers with ample entertainment choices, the car also received a custom sound system as well as Dynamat sound-deadening material to the doors, the floor, and other areas of the cockpit.
Needless to say, the 2006 Corvette C6RS turned a lot of heads at the SEMA show including Jay Leno’s, who happened to be in attendance at the 2007 SEMA show and who insisted on purchasing the first example of the C6RS on the spot. As Jay (and a select few more) would discover, purchasing a C6RS was not cheap. Truth be told, the 2006 Corvette C6RS sold for $185,000 per example, and that price did NOT include the cost of the donor Z06 which sold for approximately $65,000 when new. Unfortunately for Pratt & Miller, the late 2000s would be witness to one of the worst financial crises in nearly a century. What’s more, the 2009 model year introduced the world to the ZR1 Corvette which, while still a six-figure car, offered consumers a comparably powered car for approximately half the price of the C6RS.
In all, just seven C6RS Corvettes were built, despite Pratt & Miller’s original plan to build 25 of these powerful automobiles.
Today, Jay Leno continues to own the first example of this remarkable Corvette. The car still runs flawlessly and still passing emissions testing without issue each year (despite being 14 years old.) The C6RS can now be seen in the latest episode of Jay Leno’s Garage. Enjoy!
