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.

• We endeavour to ship all regular and stocked items on same day, next day or within 5 business days of your order being placed
• Custom orders may take longer than regular shipping times but will have information about shipping time on the listing
• We take extra care in packaging your orders to ensure you quality parts arrive safely
• PRP accepts no responsibility for damage or loss to items/products/services from courier or shipping companies once we have received receipt for the third-party service
• All Items purchased from PRP are to be installed by a qualified mechanic at a licensed workshop
• Modifying your vehicle is illegal in some states and territories, the customer acknowledges that it is their responsibility to abide by the law and take the appropriate measures to ensure that their vehicle is roadworthy
• PRP assumes no responsibility for any work carried out, modifications made or parts supplied with regards to road use, as all our products are intended for track use only

Refund requests will be reviewed case by case. Due to numerous factors including automatic & immediate 3rd party supplier purchase orders & merchant fees imposed on us, you might be liable to cover an unavoidable restocking/cancellation fee of ≥ 5%. Please review your purchase and consider contacting us for an ETA before placing an order. If your order is for a gearbox, specific turbocharger, engine build, manifold or something generally not in our extensive inventory, this restocking fee is based on the supplier and not dictated by PRP.

• Effective September 2024, refunds will not be provided for change of mind, incorrect choice or custom ordered products.
• Exchanges or refunds for items and customers that are categorized and applicable under the Australian Consumer law, requires the product/s remain unused and returned in original packaging in saleable condition at your expense to our HQ in Australia. They must return in reasonable time. PRP justifies reasonable to 60 days from date of purchase.
• If items are damaged due to courier or otherwise neglect outside of your or PRP's control, you must notify PRP within 14 days of receipt or the claim is void.
• Platinum Racing Products is not liable for refunds or replacements due to lost or stolen property. We will however attempt every effort to assist in the recovery of your goods.
• We reserve the right to offer you a full or partial refund which can be applied over staged or full payment/s within a 30 day period. 
• You agree that if you select "Authority to Leave" or similar, you waive the liability from the shipper (as per their line agreement) and Platinum Racing Products. As such, we strongly suggest sending your package to an address where someone will be available to sign for the goods and keep them secure.
• Anodizing is done in house with state of the art equipment and we hold stock of most popular colour's. We anodize generally within 48hrs. No refund nor partial will be provided if your request is inside the 48hr period and you require urgent parts however we will always do our best to meet your needs.
• There is no partial or full refunds on shipping where factors are outside of PRP's control. Any shipping estimates are to be considered estimates only.
• Silicone Hose Kits: Please note that our silicone hoses have been designed and tested for the vehicle models mentioned. They may fit other vehicles with the same engine model, however the purchase and installation is at your own risk. Due to extensive model changes throughout the years, we are unable to supply or customize hoses in alternative lengths or sizes beyond what is offered. The kits might not contain every hose you want, but we have made every effort to include the series changes to cover the majority of needs. This means we might include hose/s that don't suit your series as a bonus. We strongly advise that you carefully review all photographs provided before making your purchase. PRP does not offer refunds or partial refunds for hoses that are not included in the kit unless they are explicitly shown in the photographs and missing from your delivery.

Warranty Policy

• Warranty is for a full refund or exchange provided the item was purchased through PRP or one its approved resellers or workshops.
• Warranty is void if you tamper with products or bring them back in a different state to which they were sold to you.
• Warranty does NOT cover costs of shipping to and from in any circumstance.
• All Items/Products/Services purchased from Platinum Racing Products are to be installed by a qualified mechanic at an approved workshop and ALL warranty claims are dependent on proof of appropriate installation and verification of failure.
• Modifying your vehicle is illegal in some states and territories, the customer acknowledges that it is their responsibility to abide by the law and take the appropriate measures to ensure that their vehicle is roadworthy.
• Platinum Racing Products assumes no responsibility for any work carried out, modifications made or parts supplied with regards to road use. All our products are sold and intended for track use only.
• Lifetime warranty refers to certain Platinum Racing Products branded components and generally does not include 3rd party suppliers and their parts. Manufacturer warranty applies to items including but not limited to alternators, turbochargers, electrical sensors, ECUs and associated parts, tyres, etc.
• Due to customer and external components not supplied by PRP, flat drive oil pumps and components are limited to 1 yr warranty with specific cases reviewed before honoring. Spline drive will remain to have lifetime warranty, but again only after specific review.
• All refunds and warranty claims are based on back to base review and parts will need to be returned to HQ for assessment unless otherwise arranged.