Porsche has taken the wraps off its new for 2015 LeMans prototype race car ahead of winter testing at the Yas Marina race track in Abu Dhabi this weekend. It features the same hybrid electric powertrain as last year’s car but boasts a boatload of new aerodynamic tweaks designed to help it slip through the air more efficiently.
The rules for LeMans racing put a premium on capturing as much of the energy contained in a gallon of fuel as possible. Typically, a gasoline engine is only about 33% efficient — that is, almost 2/3 of the available energy is lost to friction and heat and does nothing to help push the car forward. Porsche has elected to use a 2.0 liter turbocharged gasoline engine in its racer. The engine is smaller than most in the series but that means it is also lighter and gets better fuel economy. In endurance racing, time spent refueling in the pits is time lost on the track, so if a car can go further between stops, it has a competitive advantage.
Porsche uses some of that waste exhaust heat to run an electric generator, or MGU-H as it is known in racing circles. The car also recaptures kinetic energy by using regenerative braking on the front wheels. The electricity is stored in a liquid cooled lithium ion battery and used to power the front wheels under acceleration. What it feels like to drive a car that has a gasoline engine turning the rear wheels and an electric motor turning the front wheels is anyone’s guess. It probably takes some getting used to.
Last year, the Porsche team, which features former Formula One driver Mark Webber, failed to get either of its LMP1 prototypes to the finish line. Both retired with mechanical issues within hours of the end of the race. No doubt, Porsche engineers have analyzed all the available data from that and other 2104 races and made adjustments to make the cars more reliable.
At a time when Formula One seems to have lost some of its luster as the pinnacle of motorsports, endurance racing is becoming more popular with race fans. The odds are that the 2015 version of the Porsche 919 will put up a stout challenge to last year’s front runners. The 2015 season kicks off at Silverstone on April 12.