86 applications were made to the ACO for entry to the 1997 running of the 24 hours. Of these 76 have been retained including the 5 who are given automatic pre-qualification.
The pre-qualification was held on 3rd and 4th May and reduced the numbers down to 52 who were admitted to the qualifiaction sessions this week (this number includes the exempted cars).
The three main classifications are 'Prototype' (including LMP650, LMP875 and WSC) GT1 and GT2. The overall numbers carried over from pre-qualification will follow the proportions of the total original entry as far as possible.
The numbers indicate the minimum weights in kilogrammes. They are 2 seater open cars with no minimum production number. They have normal or turbo engines that are power restricted. Fuel capacity is limited to 80 litres. Carbon brakes are allowed but ABS is forbidden as are cockpit controls for adjusting suspension. Engines may be up to 5.1 litres normal or 3.0 litre turbo, with a maximum of 550 Bhp. prototypes are allowed 16 inch wide tyres.
This is similar to the LMP875 and identical to the 1997 IMSA WSC classification with power restricted engines that must be derivatives of production models (up to 5.0 litres ) and non-turbo.
These can be open or closed cars that have a maximum of one door per side and 4 seats. They must be road legal with the necessary safety modifications for racing. They must be flat-bottomed between the axles and have a minimum weight of 900kg for both classes. Engines are up to 4.0 litres for turbos and 8 litres for atmospheric and a maximum Bhp of 630 (550 for GT2). Fuel capacity is limited to 100 litres. Carbon brakes are allowed for GT1 but not GT2. ABS is not permitted unless the car registered is already equipped. GT1 cars are allowed 14 inch wide tyres and GT2s 12 inch.
To equalise the competitiveness of the classes, all cars are fitted with air resrictors that limit engine performance. The dimensions of the restrictor are determined by the weight and engine capacity. Either one or two may be fitted. Where two are fitted, they are one per bank of cylinders.