Porterfield AP 919 R4 Rear

R-4 - Designed specifically for heavy duty motorsports, the R-4 brake pad was our first and original Carbon Kevlar
brake pad. Being able to maintain an average of .50 friction level within a very wide temperature range gives the R-4 pad
astounding versatility and makes it very suitable for a wide array of various track conditions. Another inherent characteristic
of our Carbon Kevlar material is how quickly the pads warm up to race temperature which is quite helpful during restarts,
and when track time is limited. Optimum R-4 operating temperatures are 450°F and above. When used with cast iron and
steel alloy rotor, the R-4 compound requires minimal bed-in period. Note: This is a full race compound, dust and squeal will
occur. It is not designed for street use.