
Race/track compound.
Designed specifically for heavy-duty motorsport, the Porterfield R-4 was Porterfield's first and original Carbon Kevlar brake pad. Its ability to maintain an average .50 friction level across a very wide temperature range provides exceptional versatility for a broad range of track conditions.
Using the latest ceramic technology, the carbon-based semi-metallic R-4 material absorbs tremendous heat and dissipates it evenly while insulating the calipers from excessive heat. The Carbon Kevlar material also warms quickly to racing temperature, which is useful during restarts and when track time is limited.
Optimum R-4 operating temperatures are 450ºF and above. When used with cast-iron and steel-alloy rotors, the compound requires minimal bedding-in. Throughout the heat range, the Carbon Kevlar material provides extremely consistent modulation and predictably smooth release characteristics up to the threshold.
Despite its high friction level and broad temperature range, the R-4 compound's properties help maximise rotor life. It is suited to road courses, oval tracks, rallies, vintage racing, autocross, club events and professional racing.
Tested and raced in numerous competition vehicles, the R-4 compound has established a reputation as a championship-winning brake-pad material.
Not for use with ceramic rotors.