GSC P-D Dual Conical Valve Spring Set w/ Titanium Retainer & Chromoly Seats | 5074

Product Fitment:

2002-2014 Subaru WRX

2004-2021 Subaru STI

The GSC Dual Conical Valve Spring Kit is a high-performance upgrade built for the turbocharged Subaru EJ engine family (EJ20/EJ25). This kit includes dual-conical valve springs, titanium retainers, and chromoly spring seats—all designed to withstand extreme valvetrain conditions and enable aggressive cam profiles, high boost levels, and elevated RPM limits.

Key Features:

• Twin conical springs: This design offers inherent damping of valvetrain harmonics, improving stability and extending component life.

• Titanium retainers: Significantly reduce rotating mass while delivering exceptional durability under stress.

• Chromoly spring seats: Precision-engineered for secure installation and reliable spring seating.

• Precision specifications: Coil bind of 0.790", install heights of 1.368" and 1.092", seat pressure around 95 lbs, and open pressure at 11.5 mm lift of approximately 233 lbs.

• High RPM/boost capability: Rated for up to 10,000 RPM and approximately 40 psi boost in performance builds.

Why Choose This Kit:
When pushing your Subaru’s EJ platform with aggressive camshafts, higher boost, or increased RPM, factory valve springs can quickly become the weak link. The GSC Power-Division Dual Conical Valve Spring Kit provides superior valve control, reduced spring surge, and improved reliability—allowing your engine to rev higher and perform better under extreme conditions.

Fitment & Installation Notes:

• Compatible with Subaru turbo EJ20 and EJ25 engines.

• Professional installation is highly recommended to ensure proper valve clearance, retainer torque, and cam/valve geometry alignment.

• After installation, follow proper break-in procedures and monitor valvetrain operation.