Many of the updates in the Corvette C6.R race cars 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 (.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 race cars 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."
Success in Sebring is not just about hardware – the human element is also crucial in an exhausting 12-hour endurance test. Corvette Racing has realigned its driver lineup in 2012 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 (Denmark) and Antonio Garcia (Spain), with 20-year-old Florida college student Jordan Taylor making his Corvette Racing competition debut as third driver. Oliver Gavin (UK) and Tommy Milner of Lake Mary, Fla., will share the No. 4 Compuware Corvette C6.R, with Richard Westbrook (UK) reprising his role as third driver in the long-distance events.
"We work together very, very well," said Magnusssen about his co-drivers. "We have similar feedback and want similar characteristics in the car. We have arrived at a solution on the seat, the pedals, and the steering wheel that we can all use without seat inserts, which will speed up driver changes. Everybody is up to speed and very fast in the car."
"It's great to welcome Tommy on board in the No. 4 Corvette C6.R," said Westbrook. "I can't argue with being paired with the reigning Le Mans champion. Olly, Tommy and I get on well, we've gelled over the winter, and we've learned what each other likes in the car. With our similar sizes, the driving position is more comfortable than last year, which is very important when you're double-stinting."
With a total of 63 entries for Sebring (33 ALMS and 30 FIA World Endurance Championship), the 17-turn, 3.7-mile circuit will feature intense racing and heavy traffic.
"It's going to be a really challenging event," said Gavin. "My expectations are there will be huge traffic and difficult situations with drivers who haven't raced at Sebring before. The pit lane has been extended to accommodate the large number of entries, which has changed the entry to the first turn. This will be an issue for the faster prototype cars because they won't be able to swing out wide to overtake and then arc into the first corner."
"Sixty-three cars at Sebring will be tough for everyone," Milner predicted. "I'm glad that I've raced there several times before and know the track well. Among all of the endurance races, Sebring is one of the most difficult driving into the night. You have the sun in your eyes in Sunset Bend and smoke from the campfires blowing across the infield. The back section, especially Turn 14, is very dark. When you don't have any reference points at night, 120 mph feels like 300 mph. Night practice here is very, very important."
Corvette first competed at Sebring in 1956 when John Fitch and Walt Hansgen raced to a Class B victory at the 12 Hours of Sebring, the first step onto the world stage that established Chevy’s sports car as a contender in top-level competition. Since then, 24 Corvettes have scored class or category victories in this legendary endurance race, including seven ALMS class wins by Corvette Racing. Armed with new machinery, an international roster of skillful drivers, and a dedicated crew, Corvette Racing is now focused on bringing home its eighth Sebring title.
The 60th Annual Mobil 1 Twelve Hours of Sebring Fueled by Fresh from Florida will begin at 10:30 a.m. on Saturday, March 17, with live video on ESPN3.com. ABC will televise the race at 12:00 p.m. EDT on Sunday, March 18.
Courtesy Rick Voegelin, Chevy Racing Communications