You're carving through your favorite canyon at high speed and, although you've been on this road many times, you've had a larger turbo and intercooler installed under the hood. You're having a blast because your car is faster than ever. As you approach the most difficult series of turns in the canyons, you see the pole that marks your usual braking point. You stand on the brake pedal and for some reason the car isn't stopping like it used to. As your car starts to slide sideways, your muscles tense as the guardrail gets closer and closer. Then "boom!" and the side of your car smashes into the guardrail. Assuming the guardrail kept your car on the road, you've got around $10,000 in damages to deal with and a serious self-confidence issue to address.
Power, power and more power. Everybody always seems so concerned with horsepower since it's probably the most gratifying part of modifying a car. (Who doesn't like getting mashed into the back of a seat by the g-forces of a high-powered street car?) The key to any performance car is total balance. If your car is going to be making more power, then its other systems (e.g., suspension, brakes, chassis) must be modified to handle it. If you want to drive fast, then you must also stop fast-and with control. The solution to balancing more power is bigger brakes.
Even though the Subaru Impreza WRX is new to the American market, manufacturers are already pumping out brake upgrade systems for the WRX. One manufacturer is Wilwood Engineering, a company that started designing brake systems and components in 1977. Originally, Wilwood manufactured brake systems and components for stock-car racing. As the company's reputation grew, enthusiasts from all forms of motorsports looked to Wilwood for enhanced braking performance.
Wilwood already offers brake upgrade kits for several other popular imports such as the Civic, Integra and RSX. With the climbing popularity and cult following of the WRX, it was a natural step for the company to produce brake systems for the car. The WRX already comes with fairly sized brakes with 11.4-in. rotors in the front and 10.3-in. rotors in the rear. However, it uses only two floating-piston calipers in the front and single-floating piston calipers in the rear. While testing has shown the WRX to have ample braking performance, the stock brakes are probably not enough for a modified car. Even with a stock horsepower car, if you want to hit the track a brake upgrade is definitely required for non-fade performance. In comparison, the Acura RSX Type-S (200 hp and 2,767 lb) has larger 11.8-in. front rotors despite having an inferior power to weight ratio to the WRX (227 hp and 3,085 lb)
Wilwood offers several upgrade packages that will be available by the time you read this. All brake kits from Wilwood include everything needed for installation, including two-piece rotors, calipers, caliper adapters and hardware, stainless-steel brake lines and Wilwood's own PolyMatrix brake pads. The two-piece rotor allows the hat and rotor to expand at different rates as they heat up so that the chances of rotor warping are reduced substantially. There are two front brake upgrades from Wilwood, including 12.19-in. rotors combined with four-piston calipers and 13.06-in. rotors combined with six-piston calipers for the ultimate in stopping power. These six piston calipers are the same billet, lightweight aluminum calipers found on the front of some NASCAR race cars. For the rear, the only upgrade is a 12.19-in. rotor in the rear clamped by four piston calipers. One problem with using a two-piece rotor on the rear of the WRX is the drum style parking brake. Fortunately, the engineers at Wilwood designed their two-piece rotor to work with the factory parking brake.
Installation of the brake kit is very straight forward and the instructions are clear and concise. If you're going to install the brake system yourself, make sure that you understand all aspects of the brake system before even attempting it. If you're not familiar with brake systems, take your car to a qualified mechanic or tuning shop for the installation. The following is the installation of the Wilwood brake upgrade using the six-piston front brakes and the four-piston rear brakes on XS Engineering's WRX.