12/14/2024
Let's talk endurance racing pit stops! Outside of top-level pro racing like IMSA and WEC, pit stops look much different that many people think due to the nature of the cars, and rules about how pit stops are performed. Below is an example of a ChampCar Endurance Series pit stop. This was when I was refueling for the 90racing team at Pittsburgh International Race Complex in October.
Because endurance racing series like Champcar, TREC, and AER require the use of 200 treadwear "street tires," it is not uncommon for teams to run for several hours on one set of tires. Most cars can in these series can race for hours on end without changing tires. And, with many of the races being 7-8 hours long, it is totally normal to see a car not change tires during a race. If tires do have to be changed, teams often only change 1-2 at a time to save time in the pits. Because 200 treadwear tires do not lose much grip as they wear, we are able to do this without affecting the car's handling.
That means that teams only need to pit for fuel. Endurance racing does not allow one driver to drive for more than two hours at a time, so the goal is to make your car fuel efficient enough to race for two hours without stopping. Most cars are able to do this now. So, if there are no cautions, pit road gets to be a VERY busy place every two hours.
Adding to the congestion, there are oftentimes more cars entered in the race than there are spaces on pit road. Typically, two cars will have to share one pitbox, so communication on pit road between teams is very important. You don't want to call your driver in only for there to be no space on pit road! At some races, like the 14 Hours of Daytona, there may be up to four teams trying to share one pit box. Talk about a traffic jam...
As for what goes on during the stops, typically several things are checked while the car is on pit road. Most series have a "minimum pit stop time" rule which requires the car to be on pit road for five minutes if they are adding fuel. This gives you about 3:30 to perform your pit stop. MUCH longer than the 30 second pit stops you see in IMSA.
During a normal pit stop, crews will refuel and change drivers. Then, check tire wear and tire pressures, clean debris from the grill and/or brake ducts, top off engine oil (and sometimes other fluids), clean the windshield, check the new drivers radio, and adjust mirrors. Some teams will also re-torque their lugnuts at every stop, and many have to add ice to the cool-suit systems in the car. Adding fuel can take up to just over two minutes on some cars, so crews do have to be quick about things. Now, envision 30-50 cars doing this all at once, and you know why people always say that pit road is pure chaos! Oh, and if you mess up the pit stop, that's it! You're probably out of contention. No pressure.
Because pit road is so chaotic, there are quite a few safety rules. While refueling, the vehicle's kill switch must be turned "off," which turns off the engine and disables all electronics. Due to the high fire risk, any crewman who are over the wall during refueling must be in full fireproof gear, and there has to be a crewman holding a fire extinguisher with the pin already pulled and pointed at the fuelman. Fuel jugs are also limited to a capacity of 5 gallons, but can be modified to pour fuel faster. Because there are so many people working on cars, all series also have a speed limit for cars on pit road. Typically 20-35 MPH depending on the track. Accidents can, and do, still happen, but they are much less common and much less severe than they were 30 years ago.
