Brake Pad Identification and Friction Surface Options Explained
Looking for some great street or racing brake pads for your muscle car, truck, or race car? You've come to the right place. From stock GM metric calipers used in plenty of disc brake conversions and in some classes of oval track racing to full on "big brake" packages, at some point in your vehicle's life you're going to need new pads. It doesn't matter if you're upgrading for a weekend track day or your race car's pads are shot and need to be replaced before the next Saturday main event, we have what you need here at Speedway Motors.
If you’re trying to match up a new set of brake pads and you’re unsure which Wilwood caliper you have, the pad infographics shown below provide the dimensions of each pad, along with the caliper that it will fit. For OE-style calipers it helps to know the Friction Materials Standards Institute (FMSI) D-number. You can usually find this number somewhere on the pad backing plate or edge of the friction material. For example, GM's extremely popular 1977-1988 "metric" calipers use a D154 pad. No matter the brand or friction material/compound, the D154 denotes the actual fitment to that caliper.
- ProMatrix- Street performance/OEM replacement pad that is quiet-running with low dust, and low rotor abrasion. Fade resistant dual sport pad for street cars that autocross or do on-track events, as well as trucks that tow or have oversize wheels/tires. Popular for drag racing and off-road.
- PolyMatrix Q- Used with aluminum rotors in Sprint or Midget racing. Q pads are a ceramic formula to be quiet and low dust, with a smooth engagement.
- PolyMatrix E- Used with iron or steel rotors. Very consistent driver feel through entire operating range. Excellent street pad that can be used for track days and autocross, but also works well off-road and for drag racing.
- PolyMatrix B - Used with iron or steel rotors. Medium-high friction, good cold response. A race only pad popular for road courses, dirt and paved oval track, and off-road use, which works good at low temperatures but gets even more aggressive as it gets hot.
- PolyMatrix A- Used with iron or steel rotors. Very consistent driver feel through entire operating range. Wilwood’s most aggressive pad for road course, paved oval and dirt.
- SmartPad BP-10, BP-20, BP-30, BP-40 - These pads get increasingly aggressive as the numbers go up. BP-10 is usually what is included in Wilwood street brake kits. BP-20 is more aggressive. BP-30 and BP-40 are serious race pads, for professional road racing and asphalt oval track, and need to get hot before they really work well
- HPS - Used on iron or steel rotors. High friction/torque hot or cold. Gentle on rotors, low noise. Much improved over stock braking.
- HP PLUS - Used on Iron or steel rotors. Extremely high friction. Works well for dirt and autocross. Elevated temperature resistance.
- BLACK - Used on iron or steel rotors. Excellent stopping power and good fade resistance at low to medium temperatures. Very rotor friendly with long pad life. Good dirt track or mild asphalt use.
- SR32 - Developed for the right fronts of dirt cars where low grip is needed to help build bias in the front brake system and help the car turn better when you have to use 4 wheel brakes.
- C1 - Designed for medium to low brake temperatures and provides good cold bite while being rotor friendly. The pad is best used on IMCA style modifieds, the fronts of "Outlaw" style modifieds, drag racing, and most street applications.
- SR33 - Developed for improved stopping power over the standard C1 compound and has a wider temperature range that will reduce brake fade. The compound is made for the front and rear of dirt cars and rear asphalt cars where a medium grip pad is needed.
- C2 - Designed for a wide range brake temperatures and provides excellent cold bite and aggressive braking power. The pad is best used on rear of IMCA style modifieds, the rears of "Outlaw" style modifieds, fronts of asphalt cars, and outlaw drag racing.
- SR34 - Developed for improved stopping power over the standard C2 compound for rear dirt cars and front asphalt cars. The higher temperature range (200-1,600 degrees) makes this pad very versatile and resistant to fade while at the same time giving you a heavy grip pad with reduced rotor wear.
Updated by Mark Houlahan
