The new McLaren P1 ‘ultimate supercar’ will have a power-to-weight ratio of over 600bhp per tonne when it goes on sale in late 2013, suggesting, if the P1 is lighter than the MP4-12C, a total output of around 720bhp.
The company will not release any information about the drivetrain, interior or specific performance, but it the engine is expected to receive some kind of hybrid assistance.
Making its public debut today at the Paris motor show, the company says the P1 takes its ‘technological and spiritual inspiration’ from the company’s Racing division and has "one simple goal….to be the best driver’s car in the world on road and track." The concept P1 shown at Paris has no interior, but the exterior is described as "more than 95 percent" of the the final production car.
It is claimed  the P1 can generate 600kg of downforce at a pace "well below" the car’s maximum speed, a figure that is around five time more than the is generated by the current 12C road car and around the same as the 12C GT3 car. Programme director Paul Mackenzie says that the P1 was designed to feel like a "proper racing car" at the push of a button, which could then be driven home in "great comfort and refinement."
Autocar has learnt the P1 will have three different ride-height modes, with the lowest for track work. This latter track mode ensures that the car’s side skirts and rear diffuser work properly but also mean that the diffuser’s carbon fibre strakes are just a couple of inches above the track surface.
The P1 uses a different core carbon fibre structure - dubbed Mono-Cage - to the 12C, which incorporates a carbon roll-bar over the cabin. The roll-bar is exposed on the outside of the vehicle and also incorporates an air scoop which feeds 'clean' (aerodynamically unruffled) air into the engine bay.
The car’s basic 'jellymould' engineering package was generated primarily by aerodynamic concerns and the desire the shrink the exterior to an absolute minimum. This package was used as the basis for three design proposals, from which this final design was chosen.
The final shape is described as more of a joint engineering/design production than a styling exercise, but Frank Stephenson says that the P1 was intended to look like a "Le Mans racer...with a long, low body, long rear deck and open mesh styling to put the mechanicals on view on help cooling" .
The car’s external appearance is driven by two main requirements: the need to get air in and around the car and the need to get heat out. The most striking thing about the P1 is the huge air intakes that have been accommodated in the doors. As well as the large intake cut into the door skin, there is second intake cut into the top of the door skin, that channels air into the rear radiators through the door structure itself.
The are three 'low temperature' radiators in the nose and much of the front-end sculpting is dedicated to directing smooth airflow into the car’s intakes. Sources say the airflow into the rear of the 12C is not as aerodynamically clean as it could be because of turbulence created by the car’s front wheel. Channeling air into the P1’s engine bay over the top of the front wing and into the door’s upper intake solves this problem.
Interestingly, the rear wing intakes close to the wheels are called 'clutch' scoops, raising the possibility that they might be used to cool some kind of KERS-type flywheel system.
The P1’s huge - double element - rear wing can automatically adjust by up to 300mm rearwards on a racetrack and by up to 120mm on the road. The pitch of the wing can increase by up to 29 degrees. It also works in the same way as F1 Drag Reduction Systems, by changing angle to allow greater straight line speeds.
Under the front of the car, ahead of the front wheels, are two flaps that operate through a 0-60 degree range and are designed to "boost downforce and aero efficiency…increasing speed and driver comfort". The flaps and rear wing work in conjunction with one another.
The extreme temperatures generated by the engine is partly expelled by a 'chimney' which exits behind the cockpit. Most heat is expelled from the tail area, which is exposed as hexagonal mesh. To maximise the surface area, the tail lights have been reduced to thin LED strips which, says design director Frank Stephenson, are legal and will appear on the production car. The final car will also get a conventional windscreen wiper, but might feature a new type of rain-repellent glass the means the wiper is rarely needed at higher speeds.
The car’s skin is made from "extraordinarily thin" carbon-fibre panels which are moulded in large sections. The whole of the rear and the whole of the front of the car are made up of one single carbon fibre moulding.
The car will be offered in left-hand drive only, scotching rumours that is could resurrect the central driving position. It is likely to carry a price tag of between £700k and £800k. The final car - and the full technical details - will be released next spring.