Pit Stop - Endurance Racing

Endurance Racing

In the various forms of sports car endurance racing, pit stops are a more leisurely affair, but no less important than in other forms of racing. While stops take longer, much more routine maintenance is scheduled during such pit stops, needed to keep the car running for as long as twenty-four hours; this includes major aerodynamic changes to deal with the changing temperature in such a long race, and replacement of certain wear-limited parts, such as brake pads. Due to the fact that the race is scheduled to last a certain length of time rather than a specific distance, pit strategies are generally not designed to be synchronized with the race distance, but rather to happen on a schedule based on the car's requirements for routine service.

Under the rules of the Automobile Club de l'Ouest (ACO) only five mechanics are permitted to work on the car. One man is permitted to fuel the car; all fuelling must be completed before any other service occurs. The other four mechanics on pit lane at any given time are typically two tire changers and two tire carriers, each of whom handles his task on only one side of the car. Automatic pneumatic jacks are used, integrated into the car itself. At all times the car's engine must be shut off during the stop, and may start only when the stop has concluded.

The Grand American Road Racing Association allows only four mechanics to service a car during a pit stop. One crew member will refuel the car while the other three are responsible for changing tires and operating the pneumatic jacks. A fifth crewmember must serve as the teams designated firefighter and must stand ready in the pit stall with a fire extinguisher while the car is being refuelled. A sixth crewmember may assist in a driver change. Neither the firefighter or driver's assistant may perform any additional service to the car itself. Unlike the ACO, Grand-Am does not force crews to wait for fuelling to complete before changing tires, and does not require the car's engine be shut off during the stop.

In endurance racing, driver changes are mandatory; the shortest endurance races are scheduled for four hours, one hour longer than the longest nonstop time permitted behind the wheel. During a pit stop with a driver change, the new driver and a driver change assistant are permitted into the pit lane. The assistant, who may not do any mechanical work on the car, is tasked with helping the current driver out of the car, removing or swapping driver seat inserts, helping the new driver into the car, and helping the new driver tightly fasten his safety harness and connect his various helmet connections to the car's systems, including the two-way team radio and the drink bottle used to stave off dehydration.

A routine pit stop with no scheduled maintenance and no driver change generally lasts from thirty to forty seconds. With a driver change included, that time increases by about ten seconds. Should there be significant scheduled maintenance, such as changing brake pads, the stop can easily last well more than a minute.

Unlike most other forms of racing, the practice of "double-stinting" or even "triple-stinting" tires is commonplace in longer races; tires hard enough to withstand the rigours of racing in the heat of the daytime may be so hard that they do not wear significantly during the nighttime hours. In a race where this is an issue, significant time can be gained by choosing to leave worn tires on the car during the first stop after they were put on the car; if the temperature drops low enough, teams may even be able to go two pit stops without changing tires.