These plumbing kits are designed to compliment Radium Engineering Subaru EJ fuel rail installations. Both kits interface with the factory feed and return hard lines in the engine bay (near the LH strut tower) and provide all the under hood fuel plumbing. Both kits are compatible with all Radium fuel rails for the Subaru EJ engines (excluding the 20-0499 Dual Injector fuel rails). All necessary fittings and hoses are included, along with an adjustable Radium Engineering fuel pressure regulator.
All Radium Engineering regulators feature the first tool-less pressure adjustment (shown below). A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased.
Two plumbing kits are offered; one that feeds the fuel rails in series, and another that feed the fuel rails in a parallel configuration. Both kits perform equally well. The end decision is based on personal preference. Scroll down for details on each kit.
IMPORTANT NOTES
1. Neither kit includes a fuel filter.
2. Neither kit is compatible with Radium dual port injector fuel rail kit 20-0499.
3. Both kits are safe to use with alcohol fuels such as methanol, ethanol, E85 etc.
4. Both kits use 3/8" (6AN) high pressure EFI fuel hose.
5. Both kits included 8AN ORB plugs for the fuel rails. Use these plugs if fuel pulse dampers are not being used.
20-0984 FUEL RAIL PLUMBING KIT, SUBARU EJ, PARALLEL
COMPATIBILITY
08-14 Subaru Impreza STi
15-21 Subaru STi
OVERVIEW
Because the hoses and fittings are consolidated, the parallel kit is a good option for cleaning up the engine bay. Each fuel rail is fed as shown in the photo above. The feed and return lines enter the MPR-RA regulator from the rear and output through the front to the fuel rails.
The regulator secures to the LH strut tower using the provided stainless steel mounting bracket.
A 0-100psi fuel pressure gauge is included for calibration. Fittings and 6AN hose are included to interface with the OEM feed and return hard lines. If aftermarket -AN hoses/lines have replaced the factory piping, this kit can still be used by changing the fittings on the regulator where the feed and return lines meet.
