Radium Engineering Fuel Plumbing Kit | Multiple Subaru Fitments (20-0629-03/5)

The Radium Subaru hanger deletes the factory post-pump filter, and this kit is where that filtration comes back.

Reusing factory lines with the Radium hanger works, but a high-flow build deserves plumbing that matches and every build needs the filter the OEM module used to provide. The Radium Engineering Fuel Plumbing Kit for late model Subarus adds an 8AN PTFE feed line from the hanger to a Radium high flow fuel filter mounted under the vehicle, 8AN hose onward to the rails, and a 6AN return from the regulator back to the hanger. Every component is E85 safe, the filter bracket uses OEM chassis holes, and billet retainers keep the lines secured. Choose the stainless or microglass filter element.

What You'll Feel

• Injector protection restored with proper post-pump filtration the hanger conversion requires
• Feed flow that matches your pumps instead of throttling through factory-size lines
• A tidy underbody install with the filter bracket on existing OEM holes, no drilling
• Secured, rattle-free lines held by billet aluminum retainers
• Ethanol confidence, with every component in the kit safe for E85

Features

• 8AN PTFE feed line routes from the Radium hanger up to the underbody-mounted Radium high flow fuel filter
• 8AN hose continues from the filter to the fuel rails; 6AN return hose routes regulator return back to the hanger
• Filter element options: 10 micron stainless (20-0629-03, cleanable) or 6 micron microglass (20-0629-05, replaceable)
• Filter bracket mounts to existing chassis holes just inside the front left wheel; no drilling or permanent modification
• Billet aluminum line retainers and 10AN ORB to 8AN male filter adapter fittings included
• All components safe for E85 and alternative fuels

The Details

This kit exists because of a design decision in the Radium hanger: the OEM fuel unit's integrated post-pump filter goes away with the conversion, and Radium requires a low-micron external filter downstream on every install. Rather than leaving that to improvisation, this kit packages the filter, the bracket engineered for the Subaru chassis, and the complete high-flow line set in one order. Flow-wise, the 8AN PTFE feed replaces the factory feed path entirely, which matters once dual pumps or E85 flow rates enter the picture, and the 6AN return completes the loop from your aftermarket regulator. Element choice follows the standard Radium logic: stainless cleans and reuses, microglass filters finer but replaces at end of service, and replacement elements for both are available separately. Radium recommends aftermarket fuel rails and a fuel pressure regulator to complete the system, and on FA20 cars (2015-2021 WRX, 2014-2018 Forester XT) remember the hanger itself also needs the 20-0850 sender adapter and an external FPR since those cars are returnless from the factory.

Kit Includes

• 1x Radium high flow fuel filter with selected element (stainless -03 or microglass -05)
• 2x 10AN ORB to 8AN male filter adapter fittings
• 8AN PTFE fuel feed hose (hanger to filter) and 8AN hose (filter to rails)
• 6AN return hose (regulator to hanger)
• Filter bracket, billet aluminum line retainers, and hardware

Applications

• 2008-2021 Subaru models running the Radium late model Subaru fuel pump hanger (sold separately)
• Covers the hanger's fitment range: 2008-2014 WRX, 2008-2021 STI, 2008-2014 Impreza and Forester, 2005-2009 Legacy and Outback, plus FA20 cars with required extras
• Aftermarket fuel rails and fuel pressure regulator recommended