R4-1 Vintage Full Race Compound – Developed using knowledge testing in the vintage racing community. Optimum uses for the R4-1, under conditions where very high friction is needed with minimal warm up time and in applications where there is difficulty in maintaining sufficient heat with conventional race pad compounds. Widely used on vintage GT and formula cars the R4-1 is also gaining popularity in off-road and rally-cross classes. Great modulation, consistent pedal feedback and rotor friendly at all temperatures as with all the other Porterfield Carbon Kevlar compounds.