As planned, the ACO is being more specific about its 2010 regulations, regarding the aerodynamics of the LMPs, and more particularly, the front bodywork. On the occasion of the 2009 “24 Heures du Mans”, the ACO promised to meet the constructors at regular intervals before proposing its regulations. On 29th and 30th June, several meetings between the ACO and the constructors took place in Le Mans. A number of points to be clarified were raised during these two days, and in particular, the need to be more precise about article 3, which concerns the front of the LMPs. The ACO presented its 2010 regulations on August 23rd during the 1,000km of Nürburgring, after sharing the broad lines of them with the constructors.

Left to be defined were the specificities of article 3 of the LMP1 / LMP2 technical regulations:

FRONT AERODYNAMICS:
The regulations regarding the front of the car, with a diffuser made of two symmetrical profiles, have been defined for 2010 as follows:
• The profiles must be in front of the front wheels’ axle (not specified in the 2009 regulations)
• The minimum thickness of the trailing edge must be equal to 3% of the maximum length of the profile and no less than 10 mm (not specified in the 2009 regulations).
• The trailing edge must be perpendicular to the profile centre line (not specified in the 2009 regulations).
• Profile extension is not permitted beyond the trailing edge (not specified in the 2009 regulations).
• The leading edge of the short profile must be rearward of the leading edge of the long profile (not specified in the 2009 regulations).
• The second profile must have a constant chord within a length of 500 mm on each side of the centre line of the car (not specified in the 2009 regulations).
• The chord may be modified beyond the 500 mm defined above for the clearance of the front wheels (not specified in the 2009 regulations).

Regulations regarding front diffuser made of one single element (no symmetrical profile):
• The minimum thickness of the trailing edge must be equal to 3% of the maximum length of the profile and no less than 10 mm. If the diffuser is longer than 1000 mm the thickness of the trailing edge will not be more than 30 mm (not précised on the 2009 regulations).

• For safety reasons, the wire meshes situated at the rear of the rear wheels must be replaced with solid elements (details in the 2010 regulations to be published shortly).
• All bodywork behind the rear wheel centre line and more than 200mm above the reference plane must form a smooth, continuous, unbroken surface without cuts, and be visible from above the car with the rear wing removed.
• For 2010 only, in order to avoid questioning the current cars, for those whose rear fenders are not entirely in compliance with the above rule, waivers could be granted by the ACO at the express and justified request of the manufacturer.

BACK AERODYNAMICS:
With these decisions, the ACO considers that it has met its own objectives as well as those of the constructors who are entered in the Le Mans‐type races, namely:
• To clarify article 3 of the technical regulations
• To reduce the number of regulation interpretations of article 3
• To avoid heavy investments for one year only (2010)
• To preserve the chances of each one of the competitors.

As regards 2011, engine equivalences, engine capacities and engine types have already been published. During the next meeting with the constructors, planned for October 6th, the ACO will submit the project concerning the LMP aerodynamics (front and rear) for final ratification.
 

Source : ACO