Process West Dual Injector TGV Deletes – Subaru WRX 01–07 / STI 01–21

This bolt-on, integrated performance upgrade addresses the two main bottlenecks in the EJ-series intake system — airflow restriction and fuel supply.

The Process West Dual Fuel Rail Tumbler Delete Kit replaces the restrictive factory assembly with precision CNC-machined billet aluminium components, providing maximum airflow and consistent fuel delivery for high-boost applications.

Billet Tumbler Delete

The factory Tumble Generator Valves (TGVs) use butterfly valves within the intake runners, creating severe restriction, especially at mid to high RPM. This billet Tumbler Delete Kit completely removes that bottleneck for unrestricted performance:

• Unrestricted Performance: CNC-machined from billet aluminium with smooth, high-flow internal runners.
• Power Gains: By improving airflow into the cylinder heads, this kit removes a major choke point, delivering measurable gains in horsepower and torque across the rev range.
• Precision Design: Features a smooth, radiused inlet and outlet profile to promote maximum laminar flow into the ports.

Dual Fuel Rails

For high-power builds running upgraded turbos, injectors, and E85 or race fuels, the factory single-feed fuel system can become a limiting factor. The integrated dual-rail setup ensures reliable fuel delivery under load:

• Consistent Fuel Pressure: Dual-rail layout supports larger injectors and maintains steady fuel flow, eliminating starvation issues under high demand.
• High-Volume Ready: Ideal for high-horsepower setups, ensuring the engine receives precise fuel delivery when running increased boost or alternate fuels.
• Integrated Design: Built directly into the TGV Delete assembly, reducing complexity and potential failure points compared to separate systems.

Vehicle Compatibility

• Subaru WRX & STI (EJ20/EJ25) 2001–2007 – GD Chassis
• Subaru STI (EJ25) 2008–2021 – GR / GV / VA Chassis