GSC Power-Division Exhaust Valve – Subaru EJ20/EJ25

GSC Power-Division Exhaust Valves – Subaru EJ20/EJ25 Turbo (32mm & 33mm)

The GSC Power-Division Exhaust Valve range for Subaru EJ20 and EJ257 turbocharged engines offers maximum durability, flow, and performance in extreme conditions. Available in both standard 32mm and +1mm oversize 33mm diameters, these valves are engineered for high-horsepower, high-EGT applications where heat resistance and reliability are critical.

Manufactured from advanced stainless and superalloy materials, these valves are swirl polished, back-cut, and micro-finished to reduce weight, improve airflow, and extend lifespan. Whether you’re chasing big boost or refining valve geometry, GSC valves are a trusted upgrade for any EJ build.

Key Features

• Available in standard 32mm and oversize 33mm (+1mm) options
• Super Alloy version withstands up to 2000°F (ideal for extreme EGT conditions)
• Back-cut and swirl-polished heads for increased flow and reduced mass
• Micro-polished stems for smoother motion and less oil retention
• Modified 23-8N or Super Alloy exhaust valve material for high-heat tolerance
• Compatible with OEM or GSC valve locks

Technical Specifications

Valve Design & Benefits

• Under-head dish machining for reduced weight
• Swirl-polished heads enhance flow without compromising strength
• Back-cut valve profile improves high-RPM performance
• Valve tips hardened or fused with a stelite wafer for wear resistance
• Adjusted valve tip lengths for proper valvetrain geometry and reduced lash setup time
• Optimised keeper groove height for balanced valve spring pressure and retainer fitment

Vehicle Compatibility

• Subaru WRX – EJ20 / EJ205 / EJ207
• Subaru WRX STI – EJ257 / EJ257B
• Subaru Forester XT / Liberty GT – EJ Turbo Platforms

Note: It is recommended not to reuse valve locks in performance applications due to wear and groove deformation. Always inspect and replace during head service or rebuild.