Audi starts the 2015 season with a fundamentally re-engineered R18 e-tron quattro. Audi will now compete with an even more efficient hybrid sportscar in the 4-megajoule class in the FIA World Endurance Championship WEC and in the highlight of the season – the 24 Hours of Le Mans.
Twice as much hybrid energy, fundamentally revised aerodynamics, the next step in lightweight design and a lot of detail work characterize the latest fifth generation Audi R18. “The possibilities within the regulations, which are valid for LMP1 sportscars since 2014, are by no means exhausted. They contain so much potential that freedom for future developments exist,” says Jörg Zander, the new Head of Technology at Audi Sport. “We expect that the technological progress resulting from the fierce competition between the four automobile manufacturers now committed to the series will be reflected in much faster lap times this season, and with the benefit of less fuel consumption.”
The R18 e-tron quattro is visibly different from its predecessor, even though its basic structure is closely related to the previous car. The fresh look results from the way the airflow is channeled around and through the front end, in the area of the sidepods and at the rear of the LMP1 prototype. Large air intakes integrated in the front wheel arches reduce the drag created by the bodywork, and result in a completely new headlight design. The light units are equipped with Matrix LED technology combined with the Audi Laserlight – two innovations that improve active safety in road traffic and which can now be ordered by Audi customers for their production cars.
While Audi adopted the monocoque, the racecar’s central safety cell, from the previous model, the front canopy, front wing and wheel arches were redesigned. Because this bodywork component also included the front crash structure, Audi completed a new crash test for the 2015 season. Modified airflow through the sidepods and a new cooler layout for the engine and hybrid system further optimizes aerodynamic drag. The engine cover, which wraps the power unit even more tightly and which tapers off significantly directly behind the cockpit, also contributes to reducing drag.
Audi also prepares two bodywork versions for the various tracks on the FIA WEC calendar again this year. Combined with optimized suspension and in close cooperation with tire partner Michelin, Audi has further improved the efficiency of its sports prototype.
Hybrid pioneer Audi also takes the next step in the area of energy recuperation. The company is the only manufacturer to date to have won the Le Mans 24 Hours with a hybrid sportscar. The R18 e-tron quattro is unbeaten in the French endurance classic since 2012. For this year, the engineers have doubled the amount of recuperated energy from two to 4 megajoules per lap at Le Mans. Energy is recuperated during braking; this energy is subsequently fed back to the front axle under acceleration. The electric motor that performs this task now produces more than 200 kW (272 hp), which is a significant increase compared to last year. For this reason, Audi has also increased the capacity of the energy accumulator. The fully enclosed flywheel energy storage system mounted in the cockpit alongside the driver stores up to 700 kilojoules of energy, which it subsequently releases to the electric motor – which is about 17 per cent more than in 2014.
Despite these performance increases, Audi has achieved the minimum weight of only 870 kilograms in this the most complex racecar category currently in existence worldwide. However, the improved hybrid power goes hand in hand with a restriction for the combustion engine. The sporting regulations stipulate an even lower fuel energy amount if the engineers opt for higher hybrid output. As a result, the R18 e-tron quattro must manage with 2.5 per cent less diesel fuel per lap than in 2014.
Not least for this reason, Audi Sport initiated lots of detail work as it further developed the four-liter V6 TDI engine to achieve the ideal consumption values. The engine which is arguably the most efficient unit in the field now produces 410 kW (558 hp). Thanks to the optimized consumption, the developers managed to overcompensate for the power loss resulting from the reduced fuel quantity. Another new rule this year, only five engines per racecar can be used throughout the entire season. The even more economical power plant continues a major trend. Audi’s TDI engine debuted at Le Mans in 2006 and had recorded eight victories by 2014. While lap times continually improved, fuel consumption decreased by 38 per cent over the same period.
As a result, the latest generation R18 emphasizes in many areas the purpose that motorsport fulfils at Audi. Since the first Audi quattro in 1980, the brand has consistently used circuit racing and rallying to develop future technologies before subsequently introducing them into production – from quattro four-wheel drive to TFSI petrol direct injection, the further development of TDI engines and innovations such as the Matrix LED light and Audi Laserlight. At the Geneva Motor Show in March, Audi unveiled two other innovations related to motorsport. For the first time, the brand showcased a hybrid model, the Q7*, which combines the e-tron quattro principle with a TDI engine. In addition, the new R8* is the first model featuring the Audi Space Frame in a multi-material construction format. In addition to aluminum, the frame includes a component made of carbon fiber reinforced plastics (CFRP), a material that is now indispensable in racing.