The rules governing both the 24 Hours and the World Endurance Championship limited use of all-wheel drive to speeds above 120 km/74 mph, eliminating the technology’s low-speed traction advantage. This rule has been dropped for 2014, and Audi has adopted a new Motor Generator Unit (MGU) to take advantage of the change. The MGU and its integrated differential sits between the front wheels where it captures kinetic energy under braking. This energy is transferred to a flywheel storage device located in the cockpit next to the driver. Under acceleration, the flywheel returns the stored electrical power to the front wheels.
“We’ve developed the entire hybrid drive from scratch again for 2014,” explains Dr. Martin Mühlmeier, Head of Technology at Audi Sport. “Specifically, it’s become even lighter and more efficient than before.” It also uses a new engine/drive system strategy. The electronic powertrain controller has new computer code to take full advantage of the championship’s new efficiency regulations. — CAS