Many novice autocross racers who want to improve their lap times start out by modifying their engines. Horsepower is certainly a huge factor when it comes to winning races on drag strips and long road courses. However, when it comes to autocross races, handling and braking performance are much more important.
Autocross Racing 101
Most autocross races are held in parking lots. The courses are built out of a series of road cones arranged into a tight series of turns. Since the courses are so small, there aren't many straight-aways long enough to take advantage of high-horsepower engines.
In fact, increasing your car's horsepower can actually hurt your autocross lap times. The courses are so tight that most cars will be confined to first and second gear in the majority of races. At low speeds, your car will be much more likely to spin its tires when you start substantially increasing your engine's horsepower. That will make your car unstable and harder to control.
Stopping Power Versus Going Power
Upgrading your car's brake system is a much better way to improve your autocross lap times. When navigating a series of tight turns, you'll constantly be slamming on your brakes after brief bursts of acceleration. Braking so aggressively will cause the stock brake systems on many cars to overheat, which severely diminishes performance.
Performance Brake Pads
The easiest and most effective modification is to install a set of performance brake pads. They're designed to work more efficiently when they get hot, so you won't experience brake fade as quickly. Performance pads also offer more biting force so you can brake quicker and more aggressively.
Performance Brake Fluid
Another easy and effective modification is performance brake fluid. It has a higher boiling point than stock fluid so it is much harder to overheat. If you overwork your stock fluid and cause it to boil, your brake pedal will become mushy and won't deliver maximum biting force. When that happens, you'll have to limp your car through the remainder of your lap, braking early and more often. Your lap time will suffer substantially in the process.
Performance Brake Rotors and Calipers
If you want to go all out, you can fully upgrade your car's brake system with a set of performance rotors and calipers. Performance rotors are generally larger than stock units, which makes them better at dissipating heat. Some are also drilled or slotted to make them lighter and even more efficient at staying cool.
Performance calipers are also usually larger than stock units. That means you can install bigger brake pads for an increased biting force. Additionally, some performance calipers have an increased number of internal pistons which allows them to grab the rotor harder for maximum stopping power.
If you aren't mechanically inclined, have your performance parts installed by a professional brake service center. The last thing you want is to install something incorrectly and have your brake system give out on you in the middle of the autocross course. Contact local brake repair services for more information and assistance.