GSC Power Division 35mm (+1mm) Intake Valve Set Stainless Alloy 21-4N Chrome Polished FA20F (Set of 8) Subaru 2015-2018 WRX
- Swirl polished heads for smoother air flow over the valve
- Back cut to reduce valve weight for higher rpm, higher boost pressure and allow for more aggressive cam profiles without increasing valve spring seat pressures.
- Valve stems are micro-polished to allow for less oil retention on the stem, which creates less drag on the stem to guide for a smoother motion.
- Intake valves are a modified 21-4n stainless and Exhausts are a modified 23-8n stainless material for high heat capacity while maintaining longevity.
- Valve tips are either hardened or have a Stellite wafer tip fused so that the tip is within 5 Rockwell C of the rocker or valve tappet for extended life and less wear
- Valve tip lengths. They have taken extra time to adjust tip heights on the applications to require less tipping of the valve to maintain proper tip height for proper valve train geometry, and to cut down on install times when setting valve lash.
- They have also adjusted the Keeper grove to properly balance intake and exhaust spring pressures to reduce the use of valve spring shims and maximize performance from their spring and retainer kits.
- Valves will work with an OEM keeper/lock or when available their upgrade keeper/lock. It's not mandatory but it is suggested that any valve lock not be reused on performance applications do to material grooving.