WRX STI Spec C Type RA-R 300 2007MY WRX STI Spec C Type RA-Rs were open for ordering at the end of October. These cars are based on the WRX STI Spec C. The wheels are changed for 18-inch (460 mm), STI-branded, Enkei-made, white wheels. The engine has been blueprinted and balanced. It produces 320 PS (235 kW; 316 hp) of power. The suspension is built with the latest STI parts from the STI catalog. The front brakes are 6-piston Brembo brakes. The turbocharger is based on the larger S203/S204 twin-scroll unit. The brakes are made to change from silver to gold when heated from usage. The rotors are slotted. An STI engineer states the 2nd R in "RA-R" to mean "radical."