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.

Browse more Radium Engineering parts at JDM Mods NQ