Supertech Black Nitride Exhaust Valves | 2002-2021 Subaru WRX & STI EJ20/EJ25

Black Nitride Exhaust Valves by Supertech

Supertech Performance uses their experience of more than 20 years in the manufacturing of racing valves, do intensive testing and work very closely with many engine builders in order to continuously improve and provide the market with the best possible product for every application. High flow rates, durability and quality are of great concern to Supertech Performance.

Black Nitride Coating

This is a hardening treatment that even though it is not widely used as the chrome coating, it has several benefits and is becoming very popular, mainly for European and Japanese applications. The microhardness is higher than the stainless steel base material, keeping good ductility beneath the hard nitrided layer (microhardness is 800HV minimum). Surface Finish is smoother than with chromed stems, having less friction between stem and guide. Value seat surface is harder with the nitrided layer, lasting longer with lead free fuels, alcohols, nitro or other "explosive" mixes. Matches any kind of seats (nodular iron seats, steel powder metal seats, hard aluminum-copper seats or beryllium copper seats).

Features

• Constructed specifically for each application
• Strict tolerances ensure the highest quality fitment
• Superfinishing reduces surface roughness and increases flow

Benefits

• Extremely durable
• Great flow characteristics

Applications

• 2002-2014 Subaru WRX
• 2004-2021 Subaru STI

What's In The Box?

• (8) Exhaust Valves

Warranty

• No Warranty