The systematically driver-oriented architecture dominates the car's interior. The driver can be regarded as an integral element of a cockpit bordered by the fascia, a high centre console and the instrument panel above it, which is angled towards the driver.
Form follows function: the Audi Le Mans quattro pursues this approach with great determination. In addition to the driver-oriented interior architecture, which continues in the design of the door cappings, it is the choice of materials that creates the functional atmosphere. A critical look from the driving seat confirms that in this `driving machine' the design and positioning of all the elements have been concentrated on essentials.
Even the contribution made by the colour scheme to the overall ambience pursues the same aesthetic and ergonomic purpose: dark, `technical' shades also create a visual link with motor sport, and the impression of professional functionality and ergonomic efficiency is borne out by the prominent use of top-quality materials and workmanship.
The footwells and footrests are fully painted to yield a surface finish that is repeated inside the boot and the engine compartment as well.
Individual areas are clearly distinguished by the use of different materials: the fascia, for instance, uses a high-grade semi-transparent woven material with a network structure; this is also to be found on the outside of the seat shells. For precision operation and to make them pleasant to the touch, the controls are of rubber and aluminium.
A non-slip material with the appearance of Neoprene is used for the shoulder area of the seat shells. These are hinged in the lumbar region and have the seat cushions upholstered with a sporty and futuristic high-tech weave. Four-point automatic-reel seat belts restrain the wearer's body effectively even at the high rates of retardation encountered on the racing circuit.
The amount of space provided ensures a high standard of ride comfort for the occupants - easily superior to what is normally available in a high-performance sports car.
There are well-positioned storage shelves in the cockpit and removable pouches behind the seat shells, which can be folded forwards. The front luggage compartment has a volume of 100 litres, enough to accommodate the weekend baggage of the car's two occupants.
All the main sources of information are directly in front of the driver, in the area behind the multifunctional sports steering wheel, the rim of which is flattened at the bottom. The instrument cluster is divided into three sections: the rectangular centre section flows in a droplet pattern into the information units at the left and right.
Whereas the revolution counter at the left, although operated digitally, has a classic circular dial, the interior designers have pursued an entirely new path for the right section of the instrument cluster. The large-format digital display uses the TFT technique and can be switched between three modes - analogue, track and MMI - by the driver.
When cruising, and in the analogue mode, the surface becomes a digital speedometer with an analogue display and an additional clock display.
Those who take the Le Mans quattro out on to the racing circuit can use the track mode to display a plan of the circuit. Information obtained by GPS is used to show the next bend and to compute the lap time. In parallel with this, the almost square central section displays information on the selected suspension settings and the gear in use.
The principal data on the engine's operating condition, for instance oil pressure and temperature, can be obtained in the MMI mode. For road use, this is where the route guidance pictograms supplied by the navigation system in the TFT display are shown.
The system is controlled from the MMI terminal, which is conveniently located on the centre console - an operating concept that has already proved convincing in the Audi A8 production car, thanks to its logically planned layout.
Another well-proven feature is operation of the sequential-shift sports gearbox by paddles behind the steering wheel. This ergonomic concept has long since proved successful in motor sport - the best example of this being the threefold Le Mans winner, the Audi R8.
The small-diameter sports steering wheel also resembles a racing-car design. There are four switches below the central impact-absorbing hub: one operates the spoiler, the next activates a `pit stop' function. This makes it much easier for the driver to comply with speed-limited zones.
The third of these easily reached and operated buttons adjusts the shock absorber settings of the Audi magnetic ride system extremely rapidly. The fourth and last steering wheel button activates the track mode in the display.
A flow of power as if from a turbine, a high maximum torque curve and a fascinating sound: the basic features of a perfect sports-car engine. This 5.0-litre V10 engine with its twin turbochargers is just as fascinating in the potential it offers as in its suitability for day-to-day use. Its `bite' in every operating range and its unrivalled willingness to rev up to high speeds are truly impressive.
An included angle of 90 degrees between the engine's cylinder banks helps to keep the entire car's centre of gravity low. It makes sensible use of the available space and does not obstruct the driver's view to the rear. A crankshaft with offset crankpins is used to ensure supreme refinement and a sporty sound.
This ten-cylinder engine has 40 valves, operated by four overhead camshafts. Both the inlet and exhaust valves have continuously variable opening periods to ensure optimum gas flow in all engine-speed ranges.
Two turbochargers driven from the exhaust and located behind the engine boost the pressure of the combustion air to a maximum of 2.0 bar before it is forced into the engine. The charge-air intercoolers 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. The two oil coolers are at the side of the engine, well positioned in the airflow behind the side inlets.
As a result of these careful design measures, the engine can develop an impressive 449 kW (610 bhp). A big contribution to this formidable output is made by the direct petrol injection (FSI) system, which 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. FSI combines outstandingly efficient power output with highly efficient combustion of the fuel.
In the Audi Le Mans quattro the ten-cylinder biturbo FSI engine is particularly pleasant on account of its willingness to rev freely and its lusty pulling power at all engine speeds. The maximum torque of 750 Newton-metres is available within an exceptionally broad engine-speed range from 1,750 to 5,800 rpm, so that unnecessarily frequent gear changes are avoided. With these basic output and torque data, the five-litre engine can catapult this two-seater car from a standstill to 100 km/h in only 3.7 seconds and continues to accelerate it until the speedometer needle reaches 200 km/h, which it does after a mere 10.8 seconds. The theoretical top speed is 345 km/h, but this is electronically governed to 250 km/h.
Despite this abundant flow of power, it is quite probable that the driver of the Audi Le Mans quattro will choose to change gear quite often at the manual selector paddles behind the steering wheel, since gear changes take only a fraction of a second and there is no clutch pedal to be operated. A short gear lever is mounted on the centre tunnel, next to the electronic parking brake control, but is used only to preselect the automatic, normal and sport modes and also to engage reverse gear.
Thanks to an electro-hydraulic system, the car can be driven away from a standstill without a clutch pedal having to be operated. In this way, the sequential-shift 6-speed gearbox offers the highest level of driver convenience as well as the dynamic gear changes expected of a sports car. The gear ratios are widely spaced, so that the driver always has the ideal gear available to make controlled use of the engine's monumental torque.
Such a powerful Audi car naturally features the quattro permanent four-wheel drive system. The Le Mans quattro, as a leading-edge technology carrier, has a version of this legendary driveline that has been adapted to suit the car's mid-engined layout and the associated axle-load distribution.
For optimal traction and dynamic road behaviour, the power from this mid-engined sports car's ten-cylinder engine is normally distributed in a ratio of 40:60 between the front and rear axles. This achieves maximum agility together with optimal traction - essentials for supreme road dynamics in all conditions and on corners of varying radii.
This version of the quattro driveline, with Torsen C inter-axle differential, is of course capable of diverting engine torque to the axle at which there is more tyre grip available, in order to suppress wheelspin. 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 percent.