Audi's Le Mans Concept Hints at new Über-car

Not wanting to be left behind by German juggernauts BMW, Mercedes and Volkswagen, it was imperative that Audi offered up something special, something unique, at the 2003 Frankfurt Auto Show.

Thankfully, Germany's oft-forgotten marque unveiled a jaw-dropping concept on which a production model quasi-supercar is almost guaranteed to be produced.

Mercedes has already officially launched its stunningly powerful SLR McLaren and BMW is well on its way to unveiling its V10-powered M5 and M6 models, both of which have been built to celebrate their respective marque's achievements in Formula One racing.

While Audi can't lay claim to an F1-inspired supercar, it does have a very viable alternative: Le Mans racing.

Audi's new "Le Mans quattro" concept study pays homage to the German automaker's recent successes in the Le Mans 24-Hours race, which is a supreme test of both driver determination and engine endurance.

And like Mercedes' SLR and BMW's M6, this sexy new two-door concept car derives its locomotion from a V10 powerplant.

The very attractive Le Mans quattro concept looks more like an Italian than something styled in Ingolstadt, but of most import is the powertrain.

A 5.0-litre V10 engine with twin-turbochargers sits behind the driver in a mid-mount position, with a vee angle of 90°.

The 10-cylinder mill has 40 valves [2 intake, 2 exhaust per cylinder], which are actuated by quad overhead camshafts and both intake and exhaust valves have continuously variable opening periods to ensure optimum fuel flow at all engine-speed ranges.

While BMW is sticking with its nat-atmo V10 engine, Audi has decided to follow Mercedes to achieve a higher power output via forced induction.

Two turbochargers driven from the exhaust and located behind the mid-mounted engine help boost the pressure of the combustion air to a maximum of 2.0 bar [29 psi] before it is forced into the engine. That's a lot of pressure.

Charge-air intercoolers cool down the ultra-dense pressurised air, which are mounted above the engine.

They are fed with air through an inlet on the body side and have an additional low-temperature cooling water circuit.

All this engineering goodness adds up to a very promising 449kW (610bhp) @ 6800rpm, which is very high in the rev range for such a large engine, and particularly one with forced induction.

Such high power levels are made possible thanks to a combination of cylinders, capacity, turbocharging and variable valve timing, but an oft-forgotten contributor is Audi's patented direct petrol injection (FSI) system.

It set new standards in the cars that won such historic victories in the 2001 and 2002 Le Mans races and in the American Le Mans Series, combining outstandingly efficient power output with highly efficient combustion of the fuel.

Despite a high-rev peak power output, the 5.5-litre V10 engine delivers maximum torque from a staggering 1750rpm.

A whopping 750Nm of torque kicks in @ 1750rpm and remains constant until 5800rpm, gifting the Audi Le Mans quattro concept with one of the flattest and longest torque curves ever seen. It has a potential powerband stretching more than 5000 revolutions per minute, which should translate into plenty of go.

Audi spinmeisters at the Frankfurt Motor Show had plenty of numbers to back up their big power figures, claiming the Le Mans quattro can hit 100km/h from standstill in 3.7 seconds, which would make it faster than Lamborghini's biggest bull, the Murcielago.

This blindingly quick time is possible thanks to the car's fairly light 1530kg kerb weight. It makes use of an aluminium Audi Space Frame (ASF) that forms the central structure and the outer skin and add-on parts use a weight-saving aluminium and carbon-fibre mix.

Audi's eye-catching new prototype will hit 200km/h in 10.8 seconds and, despite the concept study being electronically limited to a 250km/h top speed, Audi engineers reckon the sleek AWD supercar is capable of speeds nearing 350km/h.

While there is no clutch pedal on offer for would-be drivers of the Le Mans quattro concept, there is also no torque converter, meaning the 4-wheel drive transmission makes use of a sequentially shifting 6-speed semi-auto gearbox, complete with twin clutches for millisecond-quick gear changes.

The 'box will first see light of day on Audi's 2004-model 3.2-litre V6-powered TT, where two clutches are mated to two input shafts. The inner shaft drives first, third, and fifth gears and the outer shaft works with second, fourth, and sixth gears.

The gearbox's quick shifts occur because even when you have one gear engaged, the unused clutch/input shaft is prepped and waiting on another ratio, ready to snap in, equating to an extremely short-lived gear change delay.

In addition to the DSG gearbox, as Audi calls it, the head-turning Audi makes use of a very sophisticated quattro system, that allows a wide array of torque distribution between the front and rear wheels.

The Le Mans quattro's power delivery has been engineered to suit its mid-engined layout and the associated axle-load distribution. For optimal traction and dynamic road behaviour, the power from this mid-engined supercar's 10-cylinder motor is normally distributed in a ratio of 40:60, front:rear axles.

This achieves maximum agility together with optimal traction - essentials for supreme road dynamics in all conditions and on corners of varying radii.

The version of the quattro driveline [with Torsen C inter-axle differential] used in the Le Mans quattro is of course capable of diverting engine torque to the axle at which there is more tyre grip available, which is used in order to suppress wheelspin (let's hope it's switchable though). Depending on the amount of grip detected, torque distribution between the front and rear axles can be varied continuously from 20:80 to 70:30 front:rear.

The Audi Le Mans quattro, with its Jet Blue paint finish, is not only a brilliant exercise in performance engineering, it's also a very impressive car to look at.

With a wide stance and a bullish appearance on the road, the Audi has a powerful rear end that is reminiscent of the TT in a slightly absurd way. It measures 1.90 metres wide, is fairly short at 4.37 metres long and is very low 1.25 metres high. A wheelbase of 2.65 metres accommodates a surprisingly spacious cockpit and the longitudinally-installed V10 "biturbo" engine behind it.

To the rear of the doors, between the sill and the roof, there is a large outward-curving intake that supplies the V10 engine, the brakes, the oil cooler and the charge-air intercooler with sufficient air.

The Le Mans quattro concept sits on large-diameter 20-inch wheels with seven double-arm styling and the front tyres are sized 255/30 with the rears rated at 295/30. The brake discs are made from a ceramic material, with diameters of 380mm at the front and 356mm at the rear. These are clamped with killer eight-piston fixed calipers at the front and fist-type calipers at the rear.

Audi made a big statement with the Le Mans quattro concept at the 2003 Frankfurt International Motor Show, and it's safe to say that the marque will be using the twin-turbo V10 engine in its upcoming supercar that will undoubtedly go head-to-head with Mercedes, BMW, Lamborghini, Aston Martin and Ferrari.

Whether the Le Mans Quattro will be the vehicle to deliver the marque's first V10 engine is still up in the air, with insiders saying a stretched and restyled Audi TT is a more likely candidate. Either way, this exciting new concept indicates that Audi is still very much a power player not only in Germany, but on a global scale.