Nissan 240SX - Performance
Brake bias is the balance of braking power between the front and rear brakes. It is usually represented as a percentage. For example, a brake bias of 75/25 means that the front brakes get 75% of the braking power, and the rear brakes get 25% of the braking power. Brake bias controls the way that the car handles when the brakes are applied. Therefore, it is useful in changing the corner entry handling characteristics of a car if braking is necessary going into a corner. Moving the brake bias toward the front brakes makes the car tighter and more stable while braking and entering a turn. Moving the brake bias toward the rear makes the car looser while braking and entering a turn.
The front brakes should always have more braking power than the rear because the weight transfer during braking loads the front tires and unloads the rear tires. If you have too much rear brake, the rear tires will lock as weight transfers forward and makes the rear of the car lighter. However, make sure you do not have too much front brake either. Excessive front braking power can lock up the front tires and decrease the overall effectiveness of your brakes since you are not using the rear tires to slow down the car. As a starting point, try setting your brake bias between 70/30 and 80/20. Fine-tune the car from there.
Production cars do not have a brake bias adjustment. Adding a brake bias adjustment often requires extensive modifications to your car’s brake system. A dual master cylinder setup is necessary to separately control the front and rear brakes. If you plan to use your car mostly for street driving, a mild aftermarket brake upgrade will suffice for improving your braking performance. However, if you will be racing, aftermarket brakes with a brake bias adjuster can be a valuable addition in making your car perform well on the track.