Description
The Radium Engineering Top-Feed Fuel Rails for Subaru WRX/STI EJ is engineered as a purpose-built solution for enthusiasts who want the surrounding system to be easier to package, service and trust under hard use.
Why This Upgrade Matters
Fuel rails become a packaging and flow foundation once an engine moves beyond the limitations of the original fuel system. The goal is not simply a larger rail: the rail must provide the injector interface, port layout and plumbing flexibility needed to build a serviceable, stable fuel system around the engine.
Product-Specific Details
The auxiliary port is located on the top surface of the fuel rails, making this setup ideal for applications that would experience clearance issues with AVCS components. For applications that were top-feed injectors from the factory. CNC machined, anodized and compatible with E85.
Fitment & Application
Application: Subaru WRX/STI EJ
Fitment style: Application-Specific
Technical Notes
Radium performance rails commonly use anodized aluminum construction and ORB-style end ports to support configurable AN plumbing. Injector dimensions and sealing style remain application-dependent, so injector selection should be confirmed with the injector manufacturer or tuner.
Radium Part Number
RAD20-0577-02
Enthusiast Notes
For higher-power or track-focused builds, the real advantage is the freedom to design the rail, regulator, sensor and plumbing layout around the engine instead of being locked into the factory fuel hardware.
Before Ordering
Confirm engine/application, injector dimensions, required adapters, regulator strategy and whether a separate plumbing kit is needed. Fuel injectors and AN adapter fittings are not assumed to be included unless specifically listed for the selected SKU.