Radium Engineering Top Feed Fuel Rails w/ Top Port Subaru WRX / STI (EDM/JDM) 2001-2006 | 20-0577-02

Product Fitment:

01-06 Subaru Impreza WRX (JDM/EDM)

01-06 Subaru Impreza WRX STi (EDM)

01-02 Subaru Impreza WRX STi (JDM)

03-06 Subaru Impreza WRX STi (JDM)(1)

04-11 Subaru Impreza (EJ253)(1)

05-10 Subaru Forester (EJ253)(1)

05-12 Subaru Legacy (EJ253)(1)

06-09 Subaru Outback (EJ253)(1)

The Radium Engineering Top-Feed Fuel Rails (Part 20-0577-02) are precision-machined fuel delivery rails designed for Subaru EJ-series engine applications. Built from solid 6061-T6 aluminum, these rails feature a top-port design with 8AN ORB fittings, providing clearance above the injector area—ideal for engines with AVCS solenoids or tight fitment constraints.

Key Features:

• Machined from solid 6061 aluminum with a black anodized finish for durability and corrosion resistance.

• 8 AN ORB threaded ports on each rail (top-port configuration) support high-flow injector setups and flexible plumbing.

• Includes thermal insulating press-in spacers to reduce heat transfer from the intake manifold and maintain fuel temperature control.

• Compatible with pump fuel types including E85 and other high-flow systems—designed to support serious performance builds.

Why Choose These Fuel Rails?
For tuners building high-boost or high-rpm EJ-series Subaru engines, the stock side-feed rails or clearance-limited configurations can become a bottleneck. The Radium Top-Feed Rails offer improved injector compatibility, better routing for fuel feed lines, and reduced fuel system restrictions. Whether you’re running E85, upgraded injectors, or need extra space for intake/solenoid assemblies, this kit delivers reliability and flexibility.

Fitment & Installation Notes:

• Designed for Subaru EJ-series powerhouse engines — WRX/STI models and other EJ-based applications.

• Installation requires access to the intake manifold and fuel rail mounting area; check injector height and O-ring sizing (OEM 11 mm upper-O-ring spec).

• Because these rails use top-port fittings, they are especially suitable for setups with space constraints underneath the manifold or near AVCS components.

(1)The vehicles below also require part number 20-0372 adapter kit.