You might know that there's a physical difference between race car brakes and street car brakes. The size of the rotors, the materials used in the pads, and the brake lines are all going to be upgraded to handle the rigors of motorsport. But that's only part of the story. Did you know that more is going on under the skin of the vehicle as it pertains to the braking system? If not, Wyatt Knox from Team O'Neil Rally School is here to explain the differences between race car and street car braking systems.
Once you start turning a street car into a race car, each part you change will affect other parts of the car. There are wheel speed sensors, vacuum lines, and computers that talk to each other. The same is true about parts of the braking system. Race teams might keep some of the stock components as they upgrade others, but they also alter many of the pieces left behind so they don't interfere with the newer, race-ready items. For example, brake boosters get tossed, creating a very firm pedal. ABS systems are disabled, leaving the safety they provide up to the driver. Brake lines are also re-routed inside a race car to protect them.
When you build a race car straight out of the gate, you'll find that it's a bit easier to create the braking system you need, but also considerably more expensive. A racing braking system will run off an aftermarket pedal box with a brake pedal that operates two separate master cylinders. One handles the front brakes and the other operates the rear stoppers. This is so that you can alter braking bias quickly and easily to get the braking feel you desire for a given circuit.
It gets even more complicated when you're dealing with a four-wheel-drive vehicle. A hydraulic handbrake is employed to help a rally car slide through corners. When the handbrake is pulled, it opens up the center differential while also locking the rear wheels. When the lever is released, that differential is locked again and the four-wheel-drive system resumes operation.
This is a complex topic, but Knox does a fantastic job of breaking it all down.
Pun very much intended.