Ferrea Competition Plus Intake Valve - Subaru BRZ FA20, Scion FRS, Toyota 86 Stock Size - Set of 8 - F2357PFerrea Competition Plus Valves have built a reputation as the industry's most reliable extreme duty valve. To manufacture the valves we use special aerospace quality alloys, including the EV8 Z18, which provides high tensile strength. An exclusive two step slow forging process ensures proper grain flow and virtually eliminates any damage to the material structure. The valves are then heat treated and stress relieved over a 48 hour period, which is the