Following an intense preseason testing program, Corvette Racing will begin its quest for the American Le Mans Series GT championship in the 60th Annual Mobil 1 Twelve Hours of Sebring on Saturday, March 17. The event will mark the competition debut of a new generation of Compuware Corvette C6.R race cars and a revised driver lineup in the most demanding endurance race on the ALMS calendar.
Many of the updates in the Corvette C6.R racecars are the result of changes in the GT class rules for 2012. The new Corvettes are 2 inches wider than the preceding version (80.6 inches overall width). Corresponding revisions in the bodywork and suspension components complement the increased track width allowed by the regulations, with muscular fender flares covering Michelin racing tires that have been optimized for the new chassis configuration. The rear wing is mounted 75mm higher than last year, and the front fascia now bristles with dive plane "whiskers" to enhance front downforce in the close-quarter battles that are the hallmark of the GT category. The heart of the beast is an updated 5.5-liter Chevrolet small-block V-8 that breathes through twin 29.2mm intake air restrictors (0.4mm larger than in 2011) as specified by the GT regulations.
"Last year one of our competitors was granted a waiver to run a car that was 2 inches wider than the GT rules allowed, and the regulations were subsequently changed to allow all of the cars in GT to race with this increased width in 2012," said Gary Pratt, Corvette Racing team manager. "The 2-inch wider track required all-new bodywork and revised suspension components. The updated Corvette C6.R has to go through the homologation (approval) process again, so we had an opportunity to make additional refinements within the parameters of the GT regulations. GM Powertrain engineers went through a similar process with updates in engine tuning and calibrations to improve driveability and throttle response."
The wide-body Corvette C6.R racecars still retain strong links to their production counterparts. The hydroformed aluminum frame, bodywork, and aero package are derived from the Corvette ZR1 supercar. The engine is a based on the Corvette Z06's 7.0-liter naturally aspirated, all-aluminum small-block, reduced to 5.5 liters displacement in accordance with the GT regulations. This tight bond between street and track is showcased in the new 2013 Corvette 427 Convertible, the fastest, most capable Corvette convertible ever produced. The Corvette Racing program pioneered the Corvette 427 Convertible's 7.0-liter engine, lightweight carbon fiber body components, and aero enhancements.
"A wider car transfers less load under cornering, and consequently it has more lateral capacity," explained Doug Louth, Corvette Racing engineering director. "It's not as simple as just making wider fender flares, however. The project involved CFD analysis, surface optimization, and wind tunnel testing. Longer front control arms produce different loads that required new fatigue calculations, durability testing, and packaging studies.
"A key objective was to minimize drag as much as possible with the wider body, while maximizing the downforce potential that it provides," Louth noted. "Even on a high-speed circuit like Le Mans, the net result favors a wider track width in terms of overall lap time. The wider track has special requirements, and Michelin again proved to be an excellent technical partner. At every test, we had several development tires to evaluate with Michelin engineers. The same Michelin personnel develop tires for the Corvette production cars, so it's a very deep and productive relationship that encourages the transfer of technology between the two disciplines."
Meanwhile, Corvette Racing has has realigned its driver lineup to ensure that all six pilots are compatible in both physical size and setup preferences. The No. 03 Compuware Corvette is driven by Jan Magnussen and Antonio Garcia, with 20-year-old Jordan Taylor making his competition debut for the the team as third driver. Oliver Gavin and Tommy Milner will share the No. 4 Compuware Corvette C6.R, with Richard Westbrook reprising his role as third driver in the long-distance events.