Radium Engineering Dual Port Injection Fuel Rails | 2002-2014 Subaru WRX (20-0499)

Eight injectors on a four-cylinder boxer, and these rails feed all of them.

The Radium Engineering Dual Port Injection (DPI) Fuel Rails for the Subaru EJ allow two fuel injectors per cylinder runner, CNC machined and designed specifically for use with the Radium 20-0489-XX TGV housings, and NOT compatible with any other housings on the market. The rails are manufactured with large 10AN ORB end ports supporting all necessary engine power requirements, with top auxiliary ports threaded 8AN ORB for ancillary accessories. Each rail carries 4 injector ports machined for 14mm O-rings, with adapters serving both the primary and secondary injector positions. Injectors sold separately.

What You'll Feel

• Staged fueling capacity for big-power and flex fuel EJ builds, eight injectors strong
• Idle and drivability preserved by the primaries while the secondaries carry top-end demand
• Massive 10AN feed architecture with 8AN auxiliary ports for dampers and sensors
• OEM Subaru injectors reusable in the primary positions via the provided top hats

Features

• DPI fuel rails for Radium 20-0489-00/-01 TGV housing kits ONLY; not compatible with other housings
• 10AN ORB end ports; 8AN ORB top auxiliary ports; 4 injector ports per rail, 14mm O-ring machined
• Primary lower injectors: OEM Subaru (with provided top hat over the upper O-ring) or 60mm Bosch EV14 style (with provided injector seat over the lower O-ring)
• Secondary upper injectors: only 34mm Bosch EV14 style
• Verified lower primaries: ID1050/1300/1700/2600-XDS-60-14-14; many owners already run ID WRX-fitment 48.11 injectors up top
• All fuel types including E85; injectors NOT included

The Details

Dual port injection solves the flex fuel math problem, since E85's volume demand at full power would need primary injectors too large to idle cleanly, and the DPI architecture splits the duty: reasonable primaries idle and cruise, secondaries stage in as load climbs, and the tune blends them. The system dependency is absolute, with these rails machined around the Radium TGV housing kits' injector bosses, so the 20-0489 housings come first in the build plan. One plumbing note from Radium matters at ordering time: the Subaru EJ series and parallel rail plumbing kits are NOT compatible with this DPI rail kit, so DPI plumbing is configured with individual fittings per your system. Injector selection follows the documented lists, dimensions confirmed with the manufacturer.

Kit Includes

• 2x CNC machined DPI fuel rails (4 injector ports each)
• Injector top hats (OEM primary reuse) and injector seats (EV14 primary use)
• Mounting hardware
• TGV housings (20-0489-XX), injectors, and fittings NOT included

Applications

• 2002-2014 Subaru WRX and EJ-family engines running Radium 20-0489-00/-01 TGV housings
• Primaries: OEM Subaru or 60mm EV14; Secondaries: 34mm EV14 only
• NOT compatible with Radium EJ series/parallel rail plumbing kits