The race to provide more efficient production fleet vehicles will be given a healthy boost later this year when the Automobile Club de l’Ouest, the rule-writer for the Le Mans 24 Hours, unveils its plans for the future of the showpiece event.
The ACO has long touted its race as a testbed for technology, but from 2014 the French automobile club will have found a way to enhance that claim. Instead of levelling the performance of its racing cars, the ACO plans to introduce a new energy equivalency formula to balance the amount of energy carried by each vehicle, based around the equivalent of 1,500 litres of petrol for the 24 hours.
Energy from fuels and hybrid systems will be relatively easy to quantify, and manufacturers will be free to bring whatever technical solutions they believe will help them to hit the European CO2 targets set for new passenger cars in 2020 and 2025. Energy efficiency, coupled with outright performance, will be the key to success at one of the biggest motor races in the world, and the main manufacturers are beginning to sit up and take notice.
History shows that the race has been a pioneer for new technology. Diesel first made an appearance at Le Mans in 1949. In 1999, British company Zytek ran an electrical hybrid system, but the car was not developed enough to qualify for the race. Team Nasamax ran bioethanol fuel in 2003 and 2004, while Mazda engineers have recommended an electrical hybrid system supporting a rotary engine, and Peugeot will debut an electrical hybrid system with its 3.7-litre diesel engine at Le Mans this month. Audi and Aston Martin are looking at lightweight solutions, while Audi is also working on an energy recovery system using the heat from the exhaust and delivering the energy to the rear wheels.
In 2010, the V10 Judd engine that finished fourth behind the diesel Audis would have used 2,900 litres of fuel to complete the race, while the winning diesel used 2,500 litres. New engine rules introduced earlier this year reduced the capacity from 5.5 litres to 3.7 litres for a diesel engine, from 6 litres to 3.4 litres for a normally aspirated petrol engine, and 2 litres for a turbocharged engine. The reduction in power is expected to be significant, from a quoted 700bhp to 550bhp in the 900kg cars, and the fuel saving will also be noticeable, but few expect to reach the 1,500-litre limit without additional measures.
Porsche has raced the 997 GT3 RSR hybrid, with a mechanical flywheel system that spins in oil up to 40,000rpm and boosts power by 160bhp delivered to the front wheels. It also announced the 918 RSR, a racing version of its new supercar, which also features mechanical flywheel technology and is likely to be at Le Mans next year.
Peugeot’s new electrical hybrid system is scheduled to test at Le Mans this month. The 908 hybrid will store the maximum energy allowance of 0.5mJ generated under braking, and that will translate to an extra 80hp delivered to the rear wheels. Unlike the Formula One KERS system, there is no “push to pass” function allowed, and the challenge to make the batteries last for 24 hours will become a major focus for development.
Peugeot’s plans almost certainly include a new petrol engine, supported by this electrical hybrid technology.
“We are never 100% sure what will happen, but petrol engines will improve year after year,” says Jean-Philippe Peugeot, vice-chairman of the supervisory board of the PSA. “To match emission rules with diesel is expensive. Efficiency is the key, and also the price. It is cheaper to meet the emission standards with petrol.”
Mazda believes that a hydrogen hybrid system supporting a rotary engine is the answer. Tomoaki Saito, senior research engineer at the Mazda Motor Corporation, attended the Le Mans 24 Hours in 2010 and says that he was evaluating the ACO regulations to make a return to develop the new technology in racing.
“If we are able to run it, we can develop it much faster, produce more power and more efficiency,” says Saito. “The rotary engine provides good conditions to produce electrical power and we want to develop that. We need a minimum of two years and new rules are being proposed for 2014 so that makes sense.”
Wirth Research, which designs and tests its cars exclusively in virtual digital format, is hoping that Honda will bring its expertise back to endurance racing, after having worked with the Japanese firm’s performance development division on a new car for 2011 and having a coupe design for 2013.
“This concept they have for the future, which is an energy-based concept, is bang up to date,” says Nick Wirth, who believes that aerodynamic solutions will be key to the success of his new car, coupled with new technology from Honda.
Aston Martin and Audi both favour lightweight options, and the new Aston Martin Le Mans car for 2011 is said to be comfortably under the 900kg weight limit. The manufacturer is looking at hybrid systems but does not run them in its production fleet and prefers lightweight solutions to save fuel.
“Hybrid is only one of the solutions available for manufacturers and so therefore should be only one of the solutions for racing car manufacturers,” says Aston Martin Racing’s team principal George Howard-Chappell.
“If you look at what Porsche is doing with its hybrid and then you had something like a Lotus Elise, with a smaller-capacity engine and reduced emissions but which is also a very good sports car that accelerates very quickly and goes round corners very quickly, they are two extremes of the two solutions.”
Audi’s head of engine technology Ulrich Baretzky was influential in pushing the ACO towards an energy equivalence formula and famously dislikes the ecological impact of producing batteries. He prefers to invest in lightweight materials. “There is no better way to save fuel than to reduce the weight,” says Baretzky. “If you cannot cope with the weight of the hybrid, then you have to make sure that the hybrid is better than production weight, and that is not the case.”
Audi’s head of motorsport, Dr Wolfgang Ullrich, says that he wants to find a good compromise in that the technology Audi works on is future-orientated but can be financed at an acceptable level of investment. “The combination of these two things is not an easy task,” he says.
“The idea is that we should not end up with the rule book in some way enforcing technologies. There should be a chance, as there is now, that a manufacturer that thinks it has the right way to go can continue and make the best out of it,” says Ullrich.