2011 Porsche 918 RSR Concept

Porsche have revealed the RSR racing variant of the mighty Porsche 918 Spyder hypercar. First shown off at the 2011 North American International Auto Show in Detroit, the RSR combines hybrid technology that the company tested with the 997 GT3 R Hybrid in 2010. Gone is the plug-in recharging, which has been replaced with a flywheel accumulator KERS system that captures excess energy from braking.

The flywheel system is mounted where the passenger seat would usually be, and is capable of spinning up to 36,000 rpm. Mounted on the steering wheel is a button that releases this stored power for eight seconds bursts. The two electric motors are linked to allow for torque vectoring between the front wheels in order the improve traction. The direct injection V8 engine has seen further development and now revs to a crazy 10,300 rpm and has been tuned to develop 555 hp.