Ever since the small-block Chevy engine was dropped into the Corvette in 1955, Vettes have been winning races. However, through to the '80s, Chevy's attitude toward racing Corvettes was odd. "Customers are racing Corvettes? Really?" seemed to be the official line. Thanks goodness they got over that. By the late '80s, Chevy was building specially prepared Corvettes for the Corvette Challenge Series. But it was the arrival of the C5 that was the game-changer.
The basic C5 was so good that Chevrolet decided to go racing. Pratt and Miller Engineering and Fabrication was chosen to build and develop the new C5-R and organize the Corvette Racing Team. The debut 1999 season saw the team take Second place in two out of five races and two First place wins and four Second place finishes in 2000. The 2001 season was the charm. In 10 races, the C5-R took seven First place wins, six Second place finishes, plus, First and Second at Le Mans! In six seasons, the C5-R won Le Mans three times (2001, 2002, and 2004) and dominated the series in 2004 by taking First place in all 10 races and winning First and Second place at Le Mans. The C5-R would be a tough act to follow.
The C6.R, using the new all-aluminum Z06 chassis, picked up where the C5-R left off by winning 10 of the 11 races of the 2005 season, plus First and Second at Le Mans. Of the 11 races in 2006, the team won First and Second place six times. In 2007 the team won 12 of the 13 races entered. And 2008 was equally as good with the team winning 11 of the 12 races for the season. Overall, the C6.Rs won First at Le Mans four times. But fortunes changed in 2009. They won First at Le Mans, but only took First place in four of eight races. 2010 was worst, with the team only winning one of 10 races and two Second place finishes. Only slightly better was 2011 with two wins in 10 races. After analyzing the competition, the Corvette team concluded that the BMWs and Ferraris had better aerodynamics and were faster in the corners. The C6.R's lack of adequate downforce and tire slip was causing rapid tire wear and extra pit stops.
The Automobile Club de l'Quest in France and ALMS changed the rules for 2012 to allow the Corvette and Porsche teams to race wider versions of their cars. Pratt and Miller built two "wide" C6.Rs used ZR1-like front fenders and lots of little improvements. The new C6.R/ZR1 measured 80.6 inches, 2 inches wider than the previous C6.Rs. To accomplish this, the rear wheels were offset and the front A-arms were lengthened 1 inch. To cover the tires, the C6.R's fenders were puffed out some more. The additional 2 inches of track also lowered the car's center of gravity. Rule changes allowed the rear wing of the C6.R to be raised 75 mm to 25 mm below the car's roofline, creating more downforce. Up front, small dive planes (aka "whiskers") were added to the front fascia, above the splitter. The rear fascia had large cutouts that increased the efficiency of the rear diffuser and reduce drag. Side-view "mirror spoilers" were designed for minimal resistance and a little additional downforce. Even the exhaust outlet was redesigned for improved engine performance and to create some additional downforce. The wider track and body allowed a 1⁄2-inch increase in tire width. The new Michelin tire sizes were 30/68-18 for the front and 31/71-18 for the rear. Plus, the tire's compound and structure was revised. Under the hood, despite a 0.4mm increase in restrictor plate size, the 5.5-liter engine (335.63 cid) saw a slight bump in horsepower and fuel mileage thanks to a revised intake manifold.
How did the new wide-body C6.R perform on the track? The 2012 and 2013 seasons didn't see the team dominate as they did from 2005 to 2008. For 2012, in 11 races the team took four First place wins and six Second place finishes. And 2013 was better with five First place wins and two Second place finishes. Also, the team won the ALMS Manufacturer/Team Championship for 2012 and 2013. Plus the team won the ALMS Driver Championship in 2012 by Oliver Gavin and Tommy Milner and in 2013 by Antonia Garcia and Jan Magnussen. Le Mans is the grand prize in road racing. In nine seasons of racing, the Corvette Racing Team won four times, with a 1-2 finish in 2005. Bravo, C6.R!