Ferrea Racing Valve Springs and Retainers kit for Subaru Impreza WRX STI EJ20/EJ25 (2001-2018) - Reference KT4019

Ferrea Racing Reinforced Valvetrain kit for Extreme Engine Builds

The Ferrea Racing KT4019 kit represents the complete solution to finalize your Subaru Impreza WRX/STI cylinder head upgrade with EJ20 or EJ25 engines. Specifically developed for Drag Racing applications, this 64-piece kit guarantees optimal valve control under high loads and extreme RPM.

Complete kit Contents (64 Pieces)

This professional kit includes all necessary components for intake and exhaust:

• 16 dual valve springs (#S10097) in premium chrome-silicon alloy
• 16 titanium retainers (#E11064) ultra-lightweight to reduce reciprocating mass
• 16 spring seat locators (#SL1051) for optimal positioning
• 16 steel valve locks (#K10074) high-strength

Technical Specifications Ferrea KT4019

• Outer Diameter: 20.8mm / 28mm (dual spring)
• Inner Diameter: 15.88mm / 20.8mm
• Seat Pressure: 90 lbs @ 36mm
• Open Pressure: 215 lbs @ 26mm
• Coil Bind: 21.5mm
• Maximum Lift: 14mm
• Type: Dual Springs - Drag Racing Spec

Ferrea Racing Components Technology

Ferrea dual springs undergo advanced heat treatment and complete stress relief over 48 hours. This exclusive technology ensures uniform load distribution and exceptional fatigue resistance even under the most extreme racing conditions. The dual spring system offers superior heat dissipation and increased reliability compared to single springs.

Verified Compatibility

compatible with all EJ20 and EJ25 engines in Subaru Impreza WRX and STI from 2001 to 2018:

• EJ257 (STI US Market)
• EJ255 (WRX US Market)
• EJ207 (STI JDM)
• EJ205 (WRX JDM)
• EJ20X / EJ20Y

?? Warning: This kit is not compatible with FA20 engines (BRZ/GT86/2015+ WRX).

Installation and Usage

Direct bolt-on installation without modifications on any Ferrea or OEM valves. This kit is designed to handle aggressive camshafts with high lift, high RPM (up to 9000+ rpm) and high boost pressures. Essential for any forged engine build targeting 400+ horsepower or intensive competition use (Drift, Rally, Circuit, Time Attack).

Why Choose NSB Concept?

NSB Concept has been the European specialist in engine performance since 2009. Our expertise in selecting the best brands like Ferrea Racing Components guarantees competition-grade parts for your high-performance projects. Fast delivery throughout Europe Fast shipping.