Radium Subaru EJ Top Feed Fuel Rail Conversion Kit | 2004-2006 Subaru WRX STI (20-0568-02)

Side feed injectors capped the EJ257's future the day it left the factory; this kit removes the cap.

The Radium Engineering Subaru EJ Top Feed Fuel Rail Conversion Kit converts the OEM side feed injector setup to top feed, opening the high-flow injector catalog the side feed world never got. The rails are CNC machined from solid 6061 aluminum, black anodized and laser engraved, with large internal bores supporting all necessary engine power requirements and 14mm ID injector bores. Four billet anodized injector seats provide sealed receptacles for top feed injectors with 14mm lower O-rings, each rail carries three 8AN ORB threaded ports (6 total), and press-fit phenolic spacers thermally insulate against intake manifold heat transfer. All fuels including E85. Injectors sold separately, and one warning drives the whole purchase: do NOT buy "WRX fitment" injectors for this kit.

What You'll Feel

• The full modern top feed injector catalog unlocked on side feed EJ engines
• Fueling headroom for the big-turbo and E85 builds the EJ257 was destined for
• Boost-sealed injector bases via the billet anodized seat receptacles
• Six 8AN ORB ports carrying feed, crossover, regulator, damper, and gauge duty
• Cooler fuel through press-fit phenolic isolation from manifold heat

Features

• Converts the OEM side feed injector setup to top feed; high-flow injectors NOT included
• CNC machined solid 6061 aluminum rails, black anodized, laser engraved, large internal bore
• 14mm ID injector bores; 4x billet anodized, laser etched injector seats for injectors with 14mm lower O-rings
• 3x 8AN ORB threaded ports per rail (6 total)
• Press-fit phenolic spacers insulate intake manifold heat transfer; stainless hardware
• All fuel types including E85

The Details

The injector warning deserves its own paragraph, because it catches builders constantly: "WRX fitment" and "WRX top feed" injectors are made for the factory top feed cars' geometry and do NOT fit this conversion, so injector selection follows the kit's actual specification, a top feed injector with a 14mm lower O-ring seating into the Radium billet seats, with flow rates from your tuner and exact dimensions confirmed with the injector manufacturer. Fitment follows the injector style rather than the badge: USDM 2004-2006 Impreza WRX STI, 2005-2006 Legacy GT and Outback XT, and 2004-2005 Forester XT that came with side feed injectors, with country of origin determining which engines qualify. Port fittings are selected per your plumbing plan, and Radium's standing clearance advice applies around ports destined for regulators or dampers.

Kit Includes

• 2x Black anodized, laser engraved 6061 aluminum top feed conversion rails
• 4x Billet anodized, laser etched injector seats (14mm lower O-ring receptacles)
• Press-fit phenolic thermal spacers
• Stainless steel hardware
• Injectors and port fittings NOT included

Applications

• 2004-2006 Subaru Impreza WRX STI (USDM, side feed injector cars)
• 2005-2006 Legacy GT and Outback XT; 2004-2005 Forester XT (side feed injector cars)
• Top feed injectors with 14mm lower O-rings; do NOT purchase "WRX fitment" injectors