This year at the 80th running of the Le Mans sports car endurance race held in France, both Audi and Toyota made use of new technology with kinetic energy recovery systems (KERS). The 24 hours of Le Mans is the world's oldest and most gruelling endurance race, taking place annually since 1923.
The kinetic energy recovery systems, which harvest and store energy during braking and then use it in acceleration, provide cars with an energy burst when coming out of a corner. These systems are already used in Formula One where the system is limited to 400 kilojoules of energy boost per lap and the system is controlled by the driver. At Le Mans, the driver does not control the energy boost, which is used progressively and automatically at specific points on the track. The boost turns on when the cars reach a speed of 120 k.p.h. after exiting a corner where the braking has stored the energy and will produce will produce 500 kilojoules of energy.
Audi and Toyota are using different kinds of KERS, the Toyota KERS system, which powers the rear wheels, uses capacitors to store the energy, while the Audi system uses a flywheel that stores it for a shorter time and releases it more quickly.
Audi's system was developed by Williams Hybrid Power. The Audi R18 e-tron quattro, supported by Williams Hybrid Power's (WHP) electric flywheel technology, won the 80th running of the 24 hours of Le Mans and in the process made history as the first hybrid powered vehicle to finish on the podium.
2012 saw Audi race a hybrid vehicle at Le Mans for the first time, with WHP's electromechanical hybrid flywheel system assisting to power the Audi #1 and Audi #2 to first and second place respectively. The two Audi R18 e-tron quattro's dominated the race from start to finish, only relinquishing the lead once for a few laps.
WHP designed an entirely new, ultra-lightweight electric flywheel and associated power electronics for the Audi R18 e-tron quattro. The key features and benefits of the WHP system are highly suited to endurance racing and this made the WHP flywheel the prime candidate for Audi's project when compared to other technologies such as batteries, ultra-capacitors or mechanical flywheels.
Dr. Wolfgang Ullrich, Head of Audi Motorsport, said, "This is no doubt a historic victory for Audi. We were the first to win Le Mans with a direct-injection turbo gasoline engine and the first to be successful with a diesel engine. It's a great result that Audi is now the first brand to have achieved victory with a hybrid vehicle - and right on the first run, as before with the two other technologies, and - what's more - with both R18 e-tron quattro cars on the two top spots."
Ian Foley, Managing Director of Williams Hybrid Power, commented, "Our flywheel technology started its life as a motorsport application and whilst it's since been adapted for a variety of other purposes, motorsport will always be close to our heart and is the ultimate proving ground for our technology. Hopefully we have shown that innovative hybrid systems not only help the environment, but give a race car a fundamental performance boost in terms of power injection and fuel saving."
Credit: Williams Hybrid Power
Top image: LeMans