24 Hours of Le Mans: preparation of a car

An engineer from the no21 Dragonspeed Oreca 07 explained to us all about the changes they did to their car ahead of the 24 Hours of Le Mans.

• Long gears: so we can go over 330km/h
• Less camber: we change the camber angle to more vertical so that they don't overheat on the long straights. This adds to the rolling resistance, so it slightly hurts top speed, but it's needed to get to the end of the race. We have only 14 sets of tyres for the race, so we have to make each set of tyres last for 3 or 4 stints
• Less drag: this is the reason for the Le Mans kit. Every track is a trade-off between drag (how fast you go on the straights) and downforce (how fast you are able to go in the corners). Le Mans is unique because the whole track is high speed. Therefore, the manufacturers create special bodywork which is low drag and low downforce. We accept that it makes the car harder to drive in the corners, but we benefit from it on the many long straights
• At the tail, we run minimal wing, and this small piece shown in green

• The car's headlights are sufficient for racing at night, but we add some interior lighting in the cockpit, illuminated car numbers, and some small coloured lights facing forward to uniquely identify our car when it comes into the pit lane.
• The tyres: the setup of the car is as much about making the tyres last a long time as any other considerations. We search for all the usual things - good stability under braking, good traction on the corner exits, and a balanced car through the corners, but for all that, it is critical to be able to run multiple stints without hurting the tyres
• The fuel: it is an important concern at Le Mans. It takes more than 7 litres to drive a lap. So, if you have 6 litres in the car as you approach the pits, you have no choice but to come in and get fuel. If you can save just a little fuel at every lap, maybe you can arrive at the same point with 8 litres remaining and make one more lap. That would add up to 4 fewer pit stops over the course of the race.

For a 4-hour ELMS race you do not have to replace every part on the car. You might use the same brakes for 2 or 3 races, and the suspension could last the whole season. For the Le Mans 24 Hours we will start with new brakes, and freshly serviced wheel bearings, dampers and suspension. All these parts will be worn out after the 24 Hours and will need to be serviced or replaced again.

Everybody needs to prepare physically for the race. Pit stops will come around every 35 minutes, so there will be very little chance for anyone to rest!

You now know why engineers and mechanics are always working on their cars during the Le Mans week!