Girodisc Dodge Viper ACR Front Iron Rotor ConversionThe Girodisc system is a direct replacement for the OE disc however a different brake pad with an annulus (pad swept area) of 66mm or less must be used. This is done to keep the rotor weight at a reasonable level. If we manufactured a rotor with the same annulus as the OEM CCM rotors they would be unnecessarily heavy. The necessary pad shape is FMSI 1405 which we can provide in several compounds. The central hat section of our rotor is made from