Ferrea Subaru WRX STI Endurance Dual Spring Kit

Valve Spring Kit for 2004-2021 Subaru STI by Ferrea

Harmonics or high frequency fatigue is present in all racing engines and will usually destroy the valvetrain if not controlled. Properly designed valve springs will control the dominant harmonics, provide the needed stability, and reduce valvetrain component wear. Ferrea valve springs are developed from high strength alloys, including premium grade chrome silicon steel.

Our springs are heat-treated and stress relieved, which dramatically increases the spring’s life. Our valve springs provide the stability needed for high lift, high rpm racing engines, while minimizing the load loss for today’s aggressive valvetrain combinations.

Features

• Controls Dominant Harmonics
• Provides Needed Stability
• Reduce Valvetrain Component Wear
• Developed from High Strength Alloys
• Heat-Treated and Stress Relieved

Applications

• 2004 - 2014 Subaru Impreza WRX STi
• 2015 - 2021 Subaru WRX STI

What's In The Box?

• 16 - Dual Springs (S10098)
• 16 - Titanium Retainers (E11065)
• 16 - Seat Locators (SL1051)
• 16 - Valve Locks (K10074)