EVOLUTION OF THE ACO REGULATIONS IN 2007
24 Heures du Mans, American Le Mans Series, Le Mans Series:
Since its creation in 1923 the Le Mans 24-Hours race has always been a testing ground for new motorcar technologies. It is a laboratory in which safety improvements, reliability and engineering performance plus the pleasure of driving are tested and confirmed while respecting the environment.
These are key values that are dear to the heart both the Automobile Club de l'Ouest and its president Mr. Jean-Claude Plassart. "To respect this spirit our regulations are framed in such a way as to encourage manufacturers to take up new challenges. We are delighted with the recent initiative of two major manufacturers, which have accepted the challenge to race at Le Mans with a clean diesel engine. AUDI was the first to go for this technological gamble and so became the first manufacturer to win the race with diesel power in this year's Le Mans 24 Hours."
"When the A.C.O threw down the gauntlet with this diesel challenge the A.C.O. made it quite clear that it would keep a close eye on the equivalence between diesel and petrol-engined cars," the president of the centenary club continued. "Thus, we have been working in close collaboration with the manufacturers, the petrol companies and major independent engineers. From these studies and on-going analyses with very sophisticated simulation models and computer programmes we came to the conclusion that corrections had to be made but with considerable caution, all the more so as those in the running for victory were separated by small gaps."
"First of all, for 2007 we've decided to work on adjusting the quantity of energy supplied. It's a painstaking job which is of the utmost importance as we're sure that in the future manufacturers are going to come along with new technological innovations and above all with questions linked to different forms of energy."
First, a reminder that the A.C.O's rules accept two categories: Prototypes and Grand Touring Cars.
Each of these categories is divided into two groups:
" LM P1 and LM P2 for the Prototype category,
" LM GT1 and LM GT2 for the Grand Touring Car category,
The LM P2 and GT2 categories are reserved mainly for private teams and must have performances inferior to those in LM P1 and LM GT1.
The A.C.O wants to ensure that the performances in each category and group of cars are respected as follows:
" 1st level of performance: LM P1
" 2nd level of performance: LM P2
" 3rd level of performance: LM GT1
" 4th level of performance: LM GT2
Taking into account the results this year in the various events held under the "Le Mans" label (Le Mans 24 Hours, American Le Mans Series, Le Mans Series) the following modifications will be made to the 2007 technical regulations:
LM P1: Concerning the adjustments to be made to performances between petrol and diesel-engined cars, the advantages and disadvantages linked to the use of different types of engines must be taken into account. After making this clear the A.C.O considers that for 2007 in the light of the results achieved this year the size of the air restrictors, the supercharger pressures and the weight of all the LM P1s should remain identical to those of the 2006 season. The gap between the quantity of energy in a litre of diesel and a litre petrol being 10% the capacity of the diesel-engined cars' fuel tanks will be reduced by this amount to 81 litres.
LM P2: The performances of some of the LM P2 cars are very close to and indeed sometimes even better than the LM P1s on certain circuits so a reduction is necessary. The air restrictors will be 5% smaller.
In addition, a gap of 1.5% between the best LM P1 and LM P2 laps times must be respected. If the gap is under this figure the A.C.O will take steps to re-establish it at the end of the year.
LM GT1: Given that the performance and top speed of these cars are constantly increasing approaching those of the LM P2s, their air restrictors will be reduced by 5%. As the capacity of the fuel tanks has to be adjusted according to the type of energy used (petrol or ethanol; see 'fuels' below), the amount of fuel on board the car must not exceed 90 litres.
LM GT2: To maintain a reasonable gap to the GT1s the air restrictors will also be reduced by 5%. As the capacity of the fuel tanks has to be adjusted according to the type of energy used (petrol or ethanol; see 'fuels' below), the amount of fuel on board the car must not exceed 90 litres.
FUEL: In 2007, the ACO will supply only one kind of petrol and one kind of diesel for the Le Mans 24 Hours and the Le Mans Series events. To meet the requests of several entrants who want to use bio fuels, the ACO is currently evaluating the possibility of supplying a type of diesel and petrol in 2008 that contain a certain quantity of bio fuel. These fuels will be compatible with current engines.
However, the ACO agrees that the American Le Mans Series supply a third kind of fuel based on ethanol for its events in 2007. The capacity of the fuel tanks will be adjusted in such a way that the quantity of energy will be the same whether it is petrol or diesel. For safety reasons the capacity of the fuel tank cannot exceed 110 litres.