Nissan Plans Flywheel Hybrid for LeMans Race

Nissan Motor Co. plans to compete at the LeMans 24 Hours race in mid-June with a flywheel hybrid entry that can briefly boost powertrain output by 700 hp.

Nissan unveiled its GT-R LM Nismo race car this week at the Chicago auto show. The car's front wheels are powered by a twin-turbocharged 3.0-liter V-6 gasoline engine that makes about 540 hp. Nissan says the flywheel can contribute another 700 hp to the rear wheels for a few seconds.

The flywheel collects energy during braking, then releases it to the rear wheels through an electric clutch as the car accelerates out of a turn. The flywheel feature is specially valuable in the car's LMP1 class, where rules dictate maximums for fuel flow and energy consumption.

The oddly proportioned GT-R LM Nismo features a very long hood and tall wheel cowls that shroud significantly wider tires in front than in the rear (14 inches and 9 inches, respectively). The resulting body shape, including a drastically nipped rear end, is intended to confine airflow body and minimize drag from the large rear wing.

Nissan notes that the unique drivetrain accounts for half the 1,940-lb weight of the GT-R. The company concedes that the mass presents a performance problem at LeMans, where every 5 lbs of weight adds about half a second to lap times.