Radium Series Fuel Rail Plumbing Kit, DMR RA Regulator, Subaru WRX / STI / FXT / LGT (EJ20 / EJ25)

The Radium Engineering 20-0978 Series Fuel Rail Plumbing Kit is a complete underhood fuel plumbing solution for Subaru EJ-engined vehicles. Designed to complement Radium Engineering EJ fuel rail installations, this kit interfaces directly with the factory feed and return hard lines near the LH strut tower — providing all necessary fittings, hose, and an RA-Series Direct Mount Regulator (DMR) in a single package.

Two configurations are available: series and parallel fuel rail feed. Both perform equally well — the choice comes down to personal preference. Compatible with all Radium Fuel Rails for Subaru EJ engines, excluding the 20-0499 dual port injector rail kit.

RA-Series Direct Mount Regulator (DMR)

The included RA-Series FPR features industry-first tool-less pressure adjustment. A simple turn of the knob increases or decreases fuel pressure — no jam nut or set screw required. Incremental detents provide haptic feedback, with each detent delivering approximately 1psi (±0.5psi) of adjustment. The vacuum reference port swivels 360° and is double O-ring sealed, allowing the installer to point the vacuum fitting in any direction without tools.

Four interchangeable 10-32 threaded vacuum port fittings are included:

• Barbed Fitting — black zinc-plated 3/16" (5mm) steel barb, compatible with 5/32", 3/16", and 7/32" vacuum hose
• 3AN Male Fitting — black zinc-plated steel adapter for 3AN hose ends
• Push-To-Connect — nickel-plated brass with Buna-N O-rings, for 1/4" OD hard plastic tubing
• Vacuum Plug — black oxide stainless steel screw for constant (non-dynamic) fuel pressure

Key Features

• Complete underhood plumbing kit — all fittings, hose, and RA-Series DMR included
• Interfaces with factory hard lines — SAE quick connect or hose barb connections at the LH strut tower
• Includes 0-100psi fuel pressure gauge — installs at any 6AN junction before the regulator via included adapter
• Low profile 6AN swivel fittings — designed for the tight clearances of the EJ engine bay
• Reusable PushLok hose ends — customisable routing, no special tools required
• E85 and alcohol fuel safe — hose and fittings compatible with methanol, ethanol, E85, and all pump fuels
• 3/8" (6AN) high pressure EFI hose — cuttable with standard tools, no crimping required
• Series and parallel configurations available — both perform equally, choose based on preference

Vehicle Fitment

• Subaru WRX / STI — all EJ20 / EJ25 Impreza platforms
• Subaru Forester XT (FXT)
• Subaru Legacy GT (LGT)

Note: For early vehicles with an engine bay mounted fuel filter, consult the installation instructions. Not compatible with Radium 20-0499 dual port injector fuel rail kit. Fuel filter not included.

Available Part Numbers

• 20-0978 — Series Fuel Rail Plumbing Kit, DMR RA Regulator, Subaru EJ (Series feed configuration)

Why Radium Engineering?

• ✔ Designed and manufactured in the USA
• ✔ Industry-first tool-less RA-Series pressure adjustment with haptic feedback
• ✔ E85 and alcohol fuel safe throughout
• ✔ Trusted by professional motorsport teams and serious enthusiasts worldwide
• ✔ Exclusively distributed in Australia by Coore

Genuine Radium Engineering product. Stocked in Sydney for fast Australian delivery. Professional installation recommended. Fuel filter sold separately.