It won't be the first time that they've raced the car but it's the first time the cars has raced in the ALMS.
I can see this help top speed down the back straight if it's used as the car is coming out of turn 7, and obviously with fuel mileage.

"As expected, Porsche announced today in New York that the 911 GT3R hybrid will be coming to North America later this year to race in the Petit Le Mans (PLM). When the new flywheel hybrid race car was first announced this past spring, Porsche told us that it would make a decision about running in the American Le Mans Series (ALMS) after evaluating the new car's performance during its early races in Europe. After coming within two hours of winning the 24 Hours of Nurburgring in May, it was clear that the 25-percent fuel economy boost and extra power was more than enough to make up for the added weight of the hybrid drive."



Source: http://www.autoblog.com/2010/07/21/p...11-gt3r-hybrid