Porsche is set to unveil their 91 GT3 R hybrid sport car, which features a KERS system as used on the Williams F1 car

The 911 GT3 R hybrid is set for an official launch at the Geneva Motor Show in March, and features a hybrid system that uses twin electric motors mated to its familiar boxer engine, as well as a KERS system developed by the Williams F1 team.

Based on the 911 GT3 race car, the 911 GT3 R hybrid is powered by Porsche’s 4.0-litre flat-six boxer engine at the rear that produces 480bhp, combined with an electrical front axle drive with two electric motors each developing 60 kW. This makes the 911 GT3 R hybrid a four-wheel-drive. Unlike typical hybrids, the 911 GT3 R does not use batteries to power the electric motors. Instead, it has an electric flywheel power generator mounted inside the cockpit beside the driver to create electricity.

The flywheel generator acts itself as an electric motor with its rotor capable of spinning up to 40,000 rpm. It stores energy mechanically as rotation, or kinetic, energy and is charged-up whenever the driver applies the brakes, with the two electric motors reversing their function on the front axle and acting themselves as generators.

This system, which is similar to KERS in a Formula One car, has been developed by the Williams F1 team. It makes use of energy generated from the brakes to add power, which would otherwise be lost as heat energy.

"We hope that this will be just the start of the evolution of hybrid systems developed for formula one moving across to applications where they can contribute to cleaner and more powerful vehicles," said Williams' chief operating officer Alex Burns.