Radium 20-0984 EJ Parallel Fuel Rail Plumbing Kit w/RA Regulator for WRX STi

Vehicle Fitment

• 2008-2014 Subaru Impreza WRX STI (GR/GV; EJ257 2.5L H4 Turbo, AWD)
• 2015-2021 Subaru WRX STI (VA; EJ257 2.5L H4 Turbo, AWD; Base / Limited / Type RA / S209)

Fitment Notes

• Parallel plumbing kit for use with Radium EJ fuel rails only; fuel rails are not included.
• Regulator mounts on the LH (driver-side) strut tower using the supplied stainless bracket.
• Interfaces with OEM hard feed/return lines near the LH strut tower; works with -6AN aftermarket lines if fittings are changed at the regulator.
• Not compatible with Radium dual-injector rail kit 20-0499.
• Earlier EJ models may be possible but the FPR bracket location can be occupied; modification may be required--verify visually before purchase.
• Fuel types: gasoline, ethanol/E85, methanol blends (all hoses/fittings EFI-rated).
• Emissions: not CARB-exempt; not for use on pollution-controlled roads where prohibited.

Features

• True parallel (dead-end) routing feeds each rail directly for stable fuel pressure
• Radium RA-series adjustable multi-port fuel pressure regulator (tool-less adjustment)
• 360° swiveling vacuum reference port for flexible routing
• 0-100 psi mechanical fuel pressure gauge included
• High-pressure 3/8" (-6AN) EFI hose with reusable PushLok ends
• Low-profile swivel rail fittings optimized for tight EJ engine bays
• 8AN ORB rail plugs included when dampers are not used
• Alcohol-fuel compatible construction (gasoline, E85, methanol)

Specifications

• Part Number: 20-0984
• System Type: Parallel fuel rail plumbing kit (engine bay)
• Hose Size/Type: 3/8" (-6AN) EFI hose; PushLok ends
• Regulator: Radium RA-series MPR-RA, 1:1 vacuum reference
• Gauge: 0-100 psi mechanical
• Mount Location: LH strut tower bracket
• Rail Ports: 8AN ORB (with plugs when dampers omitted)
• Fuel Compatibility: Gasoline, E85, methanol blends
• Platform Codes: GR/GV (08-14), VA (15-21)

Included Components

• Radium RA-series multi-port FPR (MPR-RA)
• LH strut-tower stainless mounting bracket & hardware
• 0-100 psi fuel pressure gauge with adapter
• Cut-to-fit 3/8" (-6AN) EFI hose
• Assorted -6AN PushLok hose ends and swivel fittings
• SAE quick-connect adapters for OEM hard lines
• 8AN ORB rail port plugs (when dampers not used)
• Installation instructions

Product Description

Radium's 20-0984 is a complete, under-hood parallel fuel rail plumbing solution for EJ-powered Subaru WRX STI platforms (GR/GV 2008-2014 and VA 2015-2021). The kit mounts an RA-series adjustable regulator on the LH strut tower and uses -6AN EFI hose with low-profile swivel fittings to feed each rail directly for improved pressure stability and a tidy engine-bay layout.

All components are E85-compatible and EFI-rated, and the kit includes a 0-100 psi gauge for straightforward setup and diagnostics. It interfaces with the OEM hard lines using supplied quick-connect adapters and is not compatible with Radium's dual-injector rail (20-0499). For earlier EJ models, confirm bracket clearance before purchase.