Click Here to download installation instructions (PDF).
Depending on the vehicle's country of origin, this fuel rail conversion kit is compatible with the following OEM side feed TGVs (tumble generator valves) that came with the following Subaru models:
2004-2006 Impreza WRX STi (that came with side feed injectors)2005-2006 Legacy GT (that came with side feed injectors)2005-2006 Outback XT (that came with side feed injectors)2004-2005 Forester XT (that came with side feed injectors)THIS KIT IS NOT COMPATIBLE WITH 20-0172-01This fuel rail kit converts the OEM side feed fuel injector setup to top feed, allowing the use of high flow fuel injectors (not included). The fuel rail injector bores are 14mm ID. Each rail features a large internal bore to suit even the most fuel hungry engines. They are CNC machined from solid 6061 aluminum, black anodized, and laser engraved for a high quality surface finish. All 3 ports on each fuel rail are tapped with 8AN ORB (3/4"-16) threads
Machined phenolic mounting spacers and washers are included to completely isolate the fuel rail from heat transferred from the TGV housings and mounting bolts.
Two sets of these press-fit phenolic spacers (8 total) and matching hardware are included to suit different height fuel injectors. The kit is designed for specific upper and lower O-ring spacing, as depicted below.
The 4 billet injector seats are anodized and laser etched and are designed for 14mm diameter lower O-ring injectors.Use the tall spacers and longer mounting bolts to accomodate this size injector:Below are some of the many fuel injectors that are a direct fitment with this Radium fuel rail kit using the tall spacers:
Injector Dynamics ID725-48-14-14Injector Dynamics ID850-48-14-14Injector Dynamics ID1000-48-14-14Injector Dynamics ID1050x-48-14-14Injector Dynamics ID1300-48-14-14Injector Dynamics ID1700-48-14-14Injector Dynamics ID2000-48-14-14 Evolved Injection EI550-48-14-14Evolved Injection EI650-48-14-14Evolved Injection EI850-48-14-14Evolved Injection EI1000-48-14-14Evolved Injection EI1200-48-14-14Evolved Injection EI1300-48-14-14Evolved Injection EI2200-48-14-14Deatschwerks 17U-00-0050-4Deatschwerks 17U-00-0060-4Deatschwerks 17U-00-0072-4Deatschwerks 17U-00-0095-4 Deatschwerks 16S-12-2200-4 Use the shorter spacers and mounting bolts to accomodate this size injector:
Below are some of the many fuel injectors that are a direct fitment with this Radium fuel rail kit using the short spacers:Injector Dynamics ID850-34-14-14Injector Dynamics ID1050x-34-14-14Injector Dynamics ID1300-34-14-14Injector Dynamics ID1700-34-14-14Injector Dynamics ID2000-34-14-14 Evolved Injection DPI550-38-14-14Evolved Injection DPI650-38-14-14Evolved Injection DPI850-38-14-14Evolved Injection DPI1000-38-14-14Evolved Injection DPI1200-38-14-14Evolved Injection DPI1300-38-14-14Evolved Injection DPI2200-38-14-14RC Engineering SM2-0310RC Engineering SM2-0370RC Engineering SM2-0450Deatschwerks 16U-00-0042-4Deatschwerks 16U-00-0050-4Deatschwerks 16U-00-0065-4Deatschwerks 16U-00-0090-4Deatschwerks 16M-00-1500-4Deatschwerks 16M-00-2200-4
This fuel rail conversion kit is compatible with all fuel types including popular alcohol mixtures such as E85.
-Black Anodized Laser Etched Aluminum Fuel Rails (x2)-Green Anodized and Laser Etched Injector Seats (x4)-Phenolic Thermal Insulating Press-In Spacers, Tall (x4)-Phenolic Thermal Insulating Press-In Spacers, Short (x4)-Phenolic Thermal Insulating Press-In Bolt Washers (x4)-Stainless Steel M8x1.25 Mounting Bolts, Long (x4)-Stainless Steel M8x1.25 Mounting Bolts, Short (x4)
-Black Anodized Laser Etched Aluminum Fuel Rails (x2)-Green Anodized and Laser Etched Injector Seats (x4)-Phenolic Thermal Insulating Press-In Spacers, Tall (x4)-Phenolic Thermal Insulating Press-In Spacers, Short (x4)-Phenolic Thermal Insulating Press-In Bolt Washers (x4)-Stainless Steel M8x1.25 Mounting Bolts, Long (x4)-Stainless Steel M8x1.25 Mounting Bolts, Short (x4)-Black Anodized Aluminum 6AN Male Fittings (x4)-Black Anodized Aluminum 8AN ORB Plugs (x4)
The 20-0168-01 kit includes enough to plumb the rails in "Parallel, Flow-Through" or "Series". Refer to the More Details tab above for more information. If -8AN male fittings are required, they can be purchased here 14-0152. Two of the plugs can be used if the fuel rails will be plumbed in "Parallel, Dead End", as shown. The other two plugs can be used for the lower center ports if a fuel pulse damper is not used.
NOTE: Neither fuel rail kit comes with hoses.
The opening and closing of the injectors creates pressure pulses in the fuel rail, which can lead to unstable fuel pressure. In order to achieve a safe and consistent rail pressure, a pulse damper should be used (especially with high flow injectors). The internal diaphragm will absorb oscillating pulses and stabilize fuel pressure. This correction can be measured throughout the RPM range and can often help an erratic surging idle. The optional Radium 20-0176 fuel pulse damper can be used in any of the three -8AN ORB ports on the Subaru fuel rails.
Subaru Fuel Rail Plumbing
Because there are multiple ways to configure fuel hose routing, Radium Engineering does not include hoses in the Subaru kit. Radium offers a selection of pre-made PTFE hoses HERE, but does not offer custom made hoses or bulk-hose. To adapt -6AN hoses to the OEM feed and return hoses, use two Radium 14-0146 5/16" SAE quick disconnect fittings. Note: Subaru used barb fittings on early models.
Hose routing can be configured to mimic the factory flow path using an aftermarket fuel pressure regulator, as shown below. This is referred to as a series configuration.
Alternatively, the feed line can be split before it reaches the rails using a "Y" fitting, as shown. This creates a parallel flow-through system. The lines would then join back together after the fuel rails with another "Y" fitting or with the Radium Multi-Pump Regulator.
The last configuration is a parallel dead-end system, as shown below. If the regulator is mounted in the rear of the vehcile, another "Y" fitting could be used to split the feed line into two in the engine bay.