Electronically-Controlled quattro System For Audi’s 2014 R18 e-tron

In 2014, Audi’s two diesel-hybrid R18 e-tron quattro racecars competing in the FIA World Endurance Championship (WEC) will be relying on electrified four-wheel drive.

“Innovations only become pioneering achievements when they’re successfully used and others start to adopt them,” said Head of Audi Motorsport Dr. Wolfgang Ullrich. “Audi, like no other manufacturer, has repeatedly achieved such feats ever since the debut of quattro four-wheel drive in 1980.”

Audi stated in the DTM, as well, Audi was the first team in 1990 to use four-wheel drive in racing, just like in Super Touring Cars, starting in 1993. In the past two years, on achieving the string of success in the WEC, the brand proved that e-tron quattro – the combination of a hybrid system with four-wheel drive – offers significant advantages.

In the WEC championship, before 2014, Audi had been allowed to use four-wheel drive only above 120 kilometers per hour (74.5 mph). This year, this speed-related rule no longer applies.

Audi said four driven wheels promise to deliver traction advantages particularly at low speed, for instance when the driver accelerates on exiting a tight corner.

Audi provided some information on this year’s new e-tron system, stating a fundamentally new Motor Generator Unit (MGU), combined to a differential, sits in the monocoque at the level of the front axle. Two drive shafts connect the system to the front wheels. Under braking, the kinetic energy of the racecar is converted into electric current, which flows into a flywheel energy storage device located in the cockpit next to the driver. During acceleration, the recovered energy is converted again by the MGU and powers the front wheels.

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“We’ve developed the entire hybrid drive from scratch again for 2014,” explained Dr. Martin Mühlmeier, Head of Technology at Audi Sport. “Specifically, it’s become even lighter and more efficient than before. As of 2014, a single e-machine connected to a front-axle differential is longitudinally mounted. Furthermore, these front-wheel drive components are completely integrated into the monocoque of the R18 e-tron quattro.”

While the quattro systems of Audi’s factory-fielded rally models and touring cars between 1980 and 1997 used a mechanical connection in the form of a drive shaft between the front and rear axles, the power distribution to the front and rear wheels in the e-tron quattro four-wheel drive system is governed strictly by an electronic control unit, added Audi.