To the uninitiated, the Rolex Sports Car Series and the American Le Mans Series seem to have a lot in common. Both field prototypes alongside cars that look like street machines -- BMW M3s, Porsche 911s, and Chevrolet Corvettes -- but they have very different philosophies. The ALMS wants to attract manufacturers who spend a ton of money on high-tech prototypes and GTs that feature advanced traction control systems and lots of aerodynamic downforce.
Grand-Am, by contrast, is basically a spec formula. The Daytona Prototype class cars bear some resemblance to an ALMS P1 car, but the DP has a tube-frame chassis with carbon-fiber bodywork and a modified production engine making about 500 hp, instead of a full carbon-fiber chassis and a bespoke racing engine. Five manufacturers produce chassis within rigid Grand-Am dimensional rules at a price of about $400,000 apiece. Traction control isn't allowed. These 195-mph cars are apparently a lot of fun to drive. Hurley Haywood, three-time winner of the 24 Hours of Le Mans, says, "They bring the driver back into the equation, as there aren't a lot of electronics to get in the way." "I like these cars a lot," adds Scott Pruett, who drives the Telmex-sponsored Riley-BMW for Chip Ganassi's team and who has raced 1000-hp GTP sports cars and CART single-seaters. "You have to maximize the car, and I find that more exciting and challenging than relying on technology."
The GT class in the Rolex series is very different from the equivalent in the ALMS because many of the cars don't use production body shells; instead, they're tube-frame chassis with carbon-fiber bodies that have to fit the templates of the cars they represent, whether that's a BMW M3, a Chevy Camaro, or a Mazda RX-8. The Porsche 911s and Corvettes are based on the street machines, however. To equalize the cars, which produce between 390 and 450 hp and can run up to 180 mph, Grand-Am uses tire size, fuel-tank capacity, engine-rev restrictions, weight, air restrictors, and ride height. "Balancing the different cars is where Grand-Am does a great job," Tremblay says. There's a little bit of trepidation that Grand-Am is proposing opening up the series to GT3 versions of the Ferrari 458 Italia, the Mercedes-Benz SLS AMG, and the Audi R8, which could raise the cost of entry, but Grand-Am is determined to maintain a level playing field.