The following is excerpted from a post by J.A. Ackley on Turnology.com. You can read the entire post and view all the images by clicking on this sentence.
If you want to try endurance racing — a race more than six-hours long — you have to assess more than how much more fuel and tires you need. You should also consider other consumables — so brake management is crucial.
With a thorough and honest assessment of what you have on your car now, you can ensure your race doesn’t prematurely come to a halt due to a lack of stopping power. We asked Darrick Dong, the director of motorsports at PFC Brakes, to offer his expert insight on brake management to help you go the distance.
The rule book often restricts how much you can beef up your brake package. Keep it handy, as we discuss several aspects of your braking system to see if what you should do aligns with what you can do.
In addition to the rules, the wheel-and-tire combination determines how much you can modify the brake system. The larger the tire, the smaller the wheel, and/or the larger the amount of wheel backspace, the smaller the brake package you can run.
“The maximum package typically in a TCR car has a 35mm disc and two 25mm pads,” Dong says. “That’s an 85mm total stack of pads and discs. So, they may have to change the front brakes twice during a 24-hour period, depending on various factors.”
Despite small confines to work in, racers can get more brake material to work with. “[It may be a] 16mm pad, but it’s got 189mm worth of length into it,” Dong notes. “The pad volume is equivalent to a 25mm-thick pad.”
Front-wheel-drive cars have more mass in the front — and with that comes an increased amount of load on your brakes.
“If you’re planning to go endurance racing with a front-wheel-drive car, then the challenge is how to present a brake package big enough to support not only stopping the car, but also the engine, and the gearbox,” Dong says. “Eighty- to 90-percent of the demand is on the front [with a front-wheel-drive car]. Whereas, with a rear-wheel-drive car, you’ll have between 60- and 70-percent of the demand on the front, which has a whole different set of parameters than a front-wheel-drive car.”