Supertech Nissan GTR VR38DETT Black Nitrided Intake Valve - +1mm Oversize - Set of 12

Supertech black nitride intake valves for VR38DETT Nissan R35 GTR. These valves are available in 38.15mm (+1mm) size. Black nitride valves are made from one-piece forged stainless steel and go through a special hardening process to lessen friction between the valve and guide. The microhardness is higher than the stainless steel base material (800HV minimum), keeping good ductility beneath the hard nitrided layer. The Black Nitride surface finish is smoother than chromed stems, resulting in less friction between stem and guide, which reduces power loss due to internal engine friction at higher engine speeds.