Corvette C6R

The Chevrolet Corvette C6.R is a grand tourer racing car built by Pratt & Miller and General Motors for competition in endurance racing. It is a replacement for the Corvette C5-R racing car, applying the body style of the new C6 generation Chevrolet Corvette as well as improvements to increase the speed and reliability on the track. Since its debut in 2005, it has continued on from the previous dominance of the C5-R in its racing class with multiple American Le Mans Series championships and race wins in the Le Mans Series, FIA GT Championship, and 24 Hours of Le Mans.

Having already established the C5-R as a winning car, the development of the C6.R was more of an evolution of a design rather than an all new car which required long periods of testing and design. Pratt & Miller's process was aided by the fact that, unlike the C5-R which debuted several years after the C5 generation Corvette was on the streets, the C6.R and C6 generation Corvettes would be developed at the same time. This meant that design elements which would help the race car could be adapted to the road car, allowing the C6.R to use more exotic design features but still meet homologation requirements. In turn, this meant racing elements could be adapted to the Corvette Z06 performance car, which the C6.R shares it exterior styling with.

Much of the framework of the road legal C6 was retained on the C6.R, leading to increased use of weight-saving aluminium. The road car would also replace the C5's pop-up headlights with permanent designs integrated into the bodywork. This meant that the racing car would have better air flow over the front of the car, doing away with their replacements for the pop-up headlights which stuck out of the bodywork. The large grill opening on the car would also serve to eliminate the variety of openings on the C5-R to feed not only the brake cooling ducts, but also help with downforce by exiting back out the top of the bonnet.

Underneath, the C6.R retained much of the mechanical elements from the C5-R. The same Katech-built 7.0 litre V8 was used, but more closely based on the LS7 from the Z06. This engine, known as the LS7.R, would go on to earn the Global Motorsports Engine of the Year award in 2006 for its performance and endurance capabilities. Like the C5-R, the C6.R lacked a rear window due to structural framework and fuel tanks taking up the space behind the cockpit. However, an innovation on the C6.R was the addition of a small video camera into the rear bumper, and a monitor placed on the roof of the cockpit. This allowed the drivers a better view behind them, instead of having to rely on their side mirrors.

Another innovation was the use of an air conditioning system in the car in order to help drivers better endure high cockpit temperatures. This required the addition of a large suction fan to the rear of the car, as well as intakes integrated into the side mirrors. One innovation which the C6.R debuted in 2007 was the use of variable displacement. This system would disable half of the cylinders in the engine during caution periods in order to increase fuel economy when speed was not important. Although the system was tested during the season, its failure at the 2007 24 Hours of Le Mans led the team to remove it from the cars until it could be further evaluated.

As of the end of the 2007 season, six C6.Rs had been built by Pratt & Miller. A seventh car, used for development work, was actually built on a C5-R chassis but adapted to carry C6.R bodywork. This car has never raced and is used merely as a show car, making its public debut alongside the C6 Corvette at the 2005 North American International Auto Show.

Racing

Following the retirement of the C5-R at the end of 2004, the factory Corvette Racing squad started 2005 with two brand new C6.Rs. Unlike the previous car, which had only ran select events until it could be proven quick and reliable, the C6.Rs would compete in the full American Le Mans Series season in their first year. The season did not begin as Corvette Racing had planned however, as the equally new Prodrive Aston Martin DBR9 managed to win the event, earning Corvette Racing their first loss since the end of 2003. Prodrive returned to Europe after Sebring, and Corvette Racing was able to earn wins in each of the succeeding races that season. Even when Prodrive returned for the final two rounds, the improved Corvettes continued their streak and won both races. The C6.Rs also ventured to Europe for the 24 Hours of Le Mans, where the team were able to outlast the quicker DBR9s to earn a 1-2 victory and finish fifth and sixth overall.

In 2006, Prodrive chose to concentrate on the American Le Mans Series, giving Corvette Racing a battle throughout the season. Corvette Racing avenged their loss at Sebring, but Aston Martin managed their own victories later in the season. The two teams were close in the points championship throughout the season, before Corvette Racing managed to earn a three-point margin in the last race and won their second straight championship. At Le Mans, the Aston Martins once again faltered with reliability problems after leading the event, allowing a Corvette C6.R to finish the race fourth overall and win the GT1 class.

Following the 2006 season, Prodrive returned to Europe to concentrate on improving the DBR9 for Le Mans. This meant that Corvette Racing was left without a major opponent in the American Le Mans Series, and in fact were the only competitors in the GT1 class for nine out of twelve races that year, and easily allowing Corvette Racing to earn their third championship. At Le Mans, the Corvettes were not able to repeat their previous success as Aston Martin was finally able to reliably maintain their pace over 24 hours and earn their first class victory, leaving Corvette Racing with second.

In order to honor Canadian driver Ron Fellows, Corvette Racing entered a third C6.R at the Grand Prix of Mosport. This third car was painted in white and red colors to match the Ron Fellows Edition Corvette Z06, a limited edition road car in honor of Fellows's involvement with the Corvette Racing program since its inception. Ron Fellows drove the car for his home race.

Corvette Racing plans to continue to run the C6.Rs in the American Le Mans Series and at the 24 Hours of Le Mans in 2008.