Following on from Audi's successes with a diesel-powered racing car, Peugeot announced its decision last June to pick up the gauntlet and try to win the 24 Heures du Mans with an oilburner.
The choice of body style is that of a closed car, in line with changes to the regulations announced by the Automobile Club de l’Ouest on 16 June 2006. Equally there was also a desire to keep a link with the two-times winner of the Le Mans 24 Hours in 1992 and 1993, the Peugeot 905.
While from a technical point of view this solution presents a number of challenges (weight, height of the centre of gravity and operational issues), the Peugeot Sport team feel that it also offers advantages, particularly in terms of chassis rigidity and aerodynamics.
The monocoque body of the 908 is made of carbon fibre and is a truly closed structure, compared to the 905, which was a “racing car” with a detachable tubular rollover bar. This type of structure offers strong natural rigidity (the “eggshell” effect) and allows the weight of the monocoque body to be optimised.
Created from scratch at the beginning of 2006, Peugeot Sport’s aerodynamics department had the difficult task of designing in just a few weeks an exterior body that was both original and aerodynamically efficient.
Three months after the appointment of the aerodynamics project team leader, a model of the car was undergoing its first tests in the wind tunnel. The car's overall shape results not only from the necessary compromise between aerodynamic efficiency and drag, but also the need to provide optimum airflow to the different radiators and intercoolers located within the generously dimensioned bodywork.
Suspension, steering, brakes
Given the challenge of designing a complete car in record time and the particular constraints of the HDi DPFS engine, the Peugeot Sport team relied on proven solutions for the front and rear suspension design, the electric power steering and the brakes.
The gearbox is located longitudinally and the assembly can accommodate up to six gear ratios, the limit laid down by the regulations. It has been designed to withstand the enormous torque of the engine, while ensuring it is as lightweight and compact as possible. The gearbox is controlled electro-pneumatically.
The Peugeot 908 will be powered by a 100-degree V12 HDi diesel engine with a capacity of 5.5 litres. This is the maximum capacity permitted by the regulations and was chosen due to its efficient operation at low engine speeds. It also gives potential future development opportunities to use different grade fuels.
The choice of a 12 cylinder engine helps keep the cylinder bore diameter very close to that of a production series engine. In doing so, Peugeot can call on its extensive knowledge of diesel combustion and also ensure the engine has a reasonable piston stroke. The V12 architecture, well known for its good balance, also reduces engine vibrations to a minimum. The V angle, like the V12 architecture, makes it possible to lower the height of the engine’s centre of gravity without affecting the engine’s torsional rigidity.
Performance is expected to be a power output of over 700bhp and torque in excess of 885lb-ft.
Two diesel particulate filters are located at the end of each exhaust system and are designed to ensure smoke-free operation under all conditions. The two exhaust systems are kept as short as possible. On each side, a six-into-one exhaust manifold is connected to a Garrett turbocharger, then to a very compact diesel particulate filter before ending in a side exhaust pipe, located in front of the rear wheel.
The 908 will benefit from Peugeot Sport’s expertise and knowledge in electronics as a result of its experience with WRC cars, in particular with respect to its experience of electronically controlled differentials. Peugeot Sport will also benefit from the experience of the project’s main supplier Bosch, which will be supplying and developing the system, which operates the traction control among other elements.
- Rear central longitudinal position
- All-aluminium with one-piece aluminium cylinder block
- 12 cylinders, V angle 100°
- Capacity: 5.5 litre
- Common rail high pressure direct injection (HDi)
- Engine management system: Bosch MS17
- Power: 700bhp
- Torque: 885 lb-ft
- Gearbox: longitudinal with a maximum of 6 gear ratios
- Electro-pneumatic gearbox control
- Differential: self-locking
- Suspension, steering, brakes:
- Linked front and rear suspension
- Electric power steering
- Michelin tyres
- Wheels: BBS, magnesium
- Length: 4,650 mm
- Width: 2,000 mm
- Minimum weight: 925 kg