Audi takes one-two win at Le Mans with its diesel hybrids, Toyota third; 13th success for Audi in 16 runs
|Audi takes first and second at the 2014 Le Mans. Click to enlarge.|
In front of nearly 300,000 spectators at the 82nd running of the Le Mans 24 Hours, Marcel Fässler/André Lotterer/Benoît Tréluyer (CH/D/F) and Lucas di Grassi/Marc Gené/Tom Kristensen (BR/E/DK) secured a one-two Audi victory in the LMP1 class with the R18 e-tron quattro diesel hybrids.
It marked the 13th Le Mans success for Audi in a tough race that was open for a long time. In the first hours, the Le Mans hybrid-drive prototypes of Audi (earlier post), Porsche (earlier post) and Toyota (earlier post) were battling it out on the Le Mans high-speed circuit. The decision in favor of Audi was only made in the penultimate hour.
Each team took a different approach to implementing a hybrid drive system to meet the new efficiency-oriented WEC rules.
The Audi Audi R18 e-tron quattro couples a V6 TDI mid-engine powering the rear wheels with an e-tron quattro hybrid system at the front axle, which uses an optimized flywheel energy storage system.
For the first time, the engine’s turbocharger is linked to an electrical machine, which makes it possible to convert the thermal energy of the exhaust gas flow into electric energy—e.g., when the boost pressure limit has been reached. This energy also flows into the flywheel energy storage system. When the car accelerates, the stored energy can either flow back to the MGU at the front axle or to the innovative electric turbocharger, depending on the operating strategy.
The Toyota TS040 HYBRID features a four-wheel-drive hybrid boost system in addition to the 520 PS (513 hp, 383 kW) 3.7-liter V-8 gasoline engine. The TS040 HYBRID has a maximum power of 1000 PS (986 hp, 735 kW).
Toyota Racing is using an Aisin AW motor-generator on the front axle added to complement the Denso unit on the rear. Under deceleration, the motor-generators apply braking force in combination with traditional mechanical brakes to harvest energy, which is transferred via inverter (Aisin AW at the front, Denso at the rear) to the Nisshinbo supercapacitor bank. During acceleration, the motor/generator reverses its function, acting as a motor to deliver a 480PS power boost.
Porsche’s 919 Hybrid drive system is based on a 2.0-liter V-4 gasoline engine that is compact and lightweight. The engine is a structural component of the chassis, and reaches a maximum engine speed of approximately 9,000 rpm. It features direct injection, a single turbocharger and thermodynamic recovery capabilities. The compact unit outputs around 500 hp (373 kW).
Two different energy recovery systems harness energy to replenish the Li-ion battery pack used for energy storage and to provide boosting power. The first system is the innovative recovery of thermal energy by an electric generator powered by exhaust gases. The second hybrid system is a motor on the front axle utilizing brake recuperation to convert kinetic energy into electric energy.
The single electric motor distributes its power to the two front wheels via a differential as needed. The advanced energy management unit for the battery is located near the center of the vehicle.
Following the serious accident of Loïc Duval in Wednesday’s free practice, Audi Sport Team Joest had to prepare the Nº 1 Audi R18 e-tron quattro in record time again from scratch and to replace Loïc Duval with Marc Gené. This team was tracking to a victory on Sunday morning but faced the change of an injector and a turbocharger. With a gap of three laps, the team of Lucas di Grassi, Marc Gené and Tom Kristensen took second place.
Marcel Fässler, André Lotterer and Benoît Tréluyer took the lead for the first time on Sunday morning, shortly after 5 am, after having put consistent pressure throughout the night on the Toyota that had been leading for a long time. As the turbocharger had to be changed on their R18 as well, car Nº 2 temporarily dropped to third place before moving back to the front in a remarkable recovery during which André Lotterer also set the fastest race lap of 3m 22.567s.
Car Nº 3, with Filipe Albuquerque, Marco Bonanomi and Oliver Jarvis, was hit in the rear at high speed by a GT Ferrari on the Hunaudières straight during a safety car period in pouring rain. The powertrain of the R18 was so heavily damaged in the incident that Marco Bonanomi was forced to retire after just an hour and a half.
We’ve seen many exciting races and celebrated great victories at Le Mans but this success has a very special significance. We didn’t enter this race as favorites and in Porsche and Toyota had two very strong rivals. That we managed to win Le Mans again this time in spite of this is a fantastic achievement by the whole Audi squad. We’re tremendously happy and my thanks go to all who have made this success possible.—Professor Rupert Stadler, Chairman of the Board of Management of Audi AG