Technology always plays a role in racing. But at this year?s 24 Hours of Le Mans, which runs Saturday and Sunday, it will be front and centre in the three big ?factory? race teams that are likely to be the stars of the show.
Audi, Nissan and Toyota are all taking different technical approaches to the cars they are running.
Audi, in fact, is taking two different directions within its four-car team, entering two ?conventional? diesel-powered R18 Audi Ultra racers and two R18 e-tron Quattro diesel hybrids in the top LMP1 racing category.
Peugeot, which won Le Mans in 2009 with its own diesel-powered racers and has provided tough competition for Audi for several years will be absent from this year?s starting field.
Taking up the challenge to provide what will probably be Audi?s major opposition is Toyota, which is entering two LMP1 cars, both with gasoline-hybrid powertrains.
Nissan is backing an even more radical racer, called the DeltaWing, that falls so far outside the design norms that it will be running as an experimental vehicle that won?t be classified in the official results.
Audi has to be the pre-race favourite, having already won the 12-hour endurance race at Sebring, this year, and finishing 1-2-3-4 at 24 Hours of Spa in Belgium.
The company?s R18 Audi Ultra racer is an evolutionary development of the R18 that won at Le Mans last.
It?s a sleek enclosed-cockpit vehicle that incorporates a novel ?digital mirror? system to improve the driver?s visibility of what?s behind ? a huge problem in such tightly enclosed cars with no rear window.
Typically, the small size of outside mirrors, along with high rear fenders and big rear wings, not to mention the vibration inherent in a race car and harmful weather effects, all combine to severely limit rear vision.
Audi?s digital rearview mirror uses an innovative AMOLED display that is better than any conventional mirror, the company says.
A small camera, mounted behind the antennae on the roof of the R18, captures the action at the rear and transmits the information to the cockpit as digitalized data.
As the screens are freely programmable, Audi is also using them to display other data, including the gear that is currently engaged, the slip level of the tires and some warning lights.
In addition to two ?conventional? diesel-powered rear-wheel-drive Ultras ? powered by 3.7-litre V6 TDI engines with single variable-geometry turbochargers ? Audi will field two e-tron quattro diesel hybrids. As their name implies, they combine a diesel engine with a hybrid-electric all-wheel-drive system.
Similar in concept to the Porsche 911 GT3 R Hybrid, the R18 e-tron stores kinetic energy from braking as electricity that is then fed back through electric motors to the front wheels to provide extra driving force.
The rear wheels are driven only by the diesel engine.
Toyota?s two gasoline-electric TS030 sports racers, which will compete in the same the LMP1 prototype class as the Audis, use both gasoline and electric power to drive the rear wheels.
A 3.4-litre V8 engine is supplemented by a gearbox-mounted Denso electric motor. Energy from regenerative braking is stored in super capacitors mounted near the cockpit.
A testing crash prevented Toyota from entering the 24-hour race at Spa, so Le Mans will be the cars? first competitive outing. Toyota is treating it as a learning experience but anything can happen at Le Mans.
Nissan?s DeltaWing racer uses conventional gasoline-engine technology, but that?s about the only thing about it that is conventional.
Originally conceived as a candidate for the all-new 2012 IndyCar design, it not only incorporates a delta wing body shape, it tucks two tiny front tires closely together within the front bodywork.
After IndyCar declined to choose the DeltaWing in favour of a more normal Dallara submission, its backers turned their attention to endurance racing and received permission from the ACO, the Le Mans organizing body, to race there as an experimental entry.
Just how it will perform remains to be seen, as it defies much of racing?s conventional wisdom.
Paul Willcox, senior vice-president of Nissan in Europe, describes the experimental concept as harking back to the original motor racing trailblazers of the 1920s, who first set out just to go as fast as possible for as long as possible.
?While we can?t win with the Nissan DeltaWing, because it sits outside the regulations, we can?t lose either,? he said.
Whatever car does win, the odds are indeed high that it will feature some form of technology that is outside the racing-car norm. And that?s a good thing.