ALMS
ACO unveils 2010 Le Mans regulations
Automobile Club de l'Ouest (ACO), the organizer of the legendary 24 Hours of Le Mans and the Le Mans Series, has announced the changes for the 2010 regulations, aimed at improving and maintaining the balance between different types of chassis and ...
Published: Oct 2, 2009, 4:22 PM
Copy link
Share on Viber

Automobile Club de l'Ouest (ACO), the organizer of the legendary 24 Hours of Le Mans and the Le Mans Series, has announced the changes for the 2010 regulations, aimed at improving and maintaining the balance between different types of chassis and engine designs.
"In an unfavorable economic context, the idea was to modify the cars as little as possible," said Vincent Meaumesnil, the ACO sporting director. "All entrants want to be able to use their current cars in 2010, and possibly in 2011 and beyond. It was necessary to make a few clarifications and to modify certain points in the regulations to prevent some entrants from investing in solutions that we consider too extreme, and which go against the aims we have set ourselves -- to keep the cars' lap times above 3:30 at Le Mans".
Notably ACO indicates that cars meeting current LM P2 specifications will become eligible for the LM P1 class, with only minor modifications required. This appears to parallel the American Le Mans Series (ALMS) move to merge the two classes for the 2010 season, although it is not yet clear whether the 2010 ALMS LM P rules are an exact match for the 2011 Le Mans LM P1 rules.
The ACO released specific details for these bodywork changes:
At the rear:
Closing of the part behind the rear wheels. The use of grills or fairings to cover the rear wheel above the axis of the axle will no longer be allowed. The bodywork must be closed in this area and must carry the rear lights, rear stop lights and indicators.
On the sides:
Bodywork located at the rear of the axis of the rear wheels and above the reference plate must form a smooth, continuous, unbroken surface of convex form only, without cuts. It must not be set back more than 100mm in relation to the width of the bodywork at the axis of the rear axle (measured horizontally).
At the front:
Confirmation within 15 days of the aerodynamic definition of the front of the cars. It is currently under study and consultation with the manufacturers taking into account the technical feasibility and cost issues.
In addition, ACO again adjusted the balance of performance between the turbodiesel engines (currently Peugeot and Audi), the purpose-built prototype racing engines and the production-based engines, by altering the maximum restrictor sizes and boost pressures for each type.
Diesel engines (5.2L to 5.5L)
Restrictor size 37.5 mm (was 37.9 mm)
Boost pressure 2.59 bar (was 2.75 bar)
Closed-cockpit restrictor increase 0.3 mm (was 0.4 mm)
Racing petrol engines (5.5L to 6.0L)
Restrictor size 33.3 mm (was 32.5 mm)
Closed-cockpit restrictor increase 0.3 mm (was 0.3 mm)
Production (LM GT1) petrol engines (5.5L to 6.0L)
Restrictor size 33.3 mm (was 32.7 mm)
Over 8 cyliner restrictor increase 0.2 mm (was 0.4 mm)
Closed-cockpit restrictor increase 0.3 mm (was 0.3 mm)
For the Le Mans Series entrants, three engines will be available for the full 2010 season, instead of the current requirement of two consecutive races per engine.
There are no changes to the LM GT2 regulations, and ACO intends to make an announcement about the future of the LM GT1 category -- which has already been dropped by ALMS -- at the end of September.
We want your opinion!
What would you like to see on Motorsport.com?
Take our 5 minute survey.
- The Motorsport.com Team
Read and post comments
Read also :
Share Or Save This Story
Copy link
Share on Viber
Previous article Series notes on O'Connell 100th start
Next article Mid-Ohio: Porsche Motorsport qualifying report
Top Comments
There are no comments at the moment. Would you like to write one?
View More & Comment
Latest news

Barcelona set to host IndyCar race in 2027 under multi-year deal
IndyCar
Indy IndyCar 1 h
Barcelona set to host IndyCar race in 2027 under multi-year deal

Winners and losers from a Chase-altering NASCAR Cup race at Phoenix
NASCAR Cup
NAS NASCAR Cup
Phoenix II
3 h
Winners and losers from a Chase-altering NASCAR Cup race at Phoenix

Heart of Racing rules Valkyrie GTP step next year ‘too soon’ for IMSA standout Barrichello
IMSA
IMSA IMSA 3 h
Heart of Racing rules Valkyrie GTP step next year ‘too soon’ for IMSA standout Barrichello

Sergio Perez: Debut Cadillac season "without a doubt one of my best years"
Formula 1
F1 Formula 1
United States GP
3 h
Sergio Perez: Debut Cadillac season "without a doubt one of my best years"
Subscribe and access Motorsport.com with your ad-blocker.
From Formula 1 to MotoGP we report straight from the paddock because we love our sport, just like you. In order to keep delivering our expert journalism, our website uses advertising. Still, we want to give you the opportunity to enjoy an ad-free and tracker-free website and to continue using your adblocker.
You have 2 options:
- Become a subscriber.
- Disable your adblocker.
Subscribe now Already subscribed? Sign in here
Already disabled your adblocker?
Reload page
Manage Alerts
Subscribe