Radium Fuel Pressure Regulator Kit | 2008-2021 Subaru STI

2008+ STi Fuel Pressure Regulator Kit by Radium

This kit is designed for use in the USDM 2008-2017 Subaru WRX STi (EJ257 only) and replaces the OEM fuel pressure regulator and damper assembly. The factory STi fuel line routing uses a quasi dead-end system that circulates fuel through the regulator, bypassing the engine. Fuel is only routed to the engine when there is demand.

The Radium FPR kit replaces the factory regulator and re-routes fuel to cycle through the engine's rails before reaching the regulator, and returning to the tank. This is the preferred fuel line routing by Subaru tuners trying to address stumbling issues. The Radium Fuel Pressure Regulator offers adjustment from 20psi-up with a 1:1 vacuum reference. Interchangeable orifices allow the user to tune the regulator for any fuel pump flow.

The kit installs in the same location as the OEM fuel pressure regulator. Also included are vacuum hose and fittings to re-route the vacuum reference line from the #4 cylinder runner to the intake manifold plenum for a more stable vacuum signal.

Features

• Replaces the factory regulator and re-routes fuel to cycle through the rails before reaching the regulator
• adjustment from 20psi-up with a 1:1 vacuum reference
• Interchangeable orifices allow the user to tune the regulator for any fuel pump flow
• installs in the same location as the OEM fuel pressure regulator
• Includes vacuum hose and fittings to re-route the vacuum reference line from the #4 cylinder runner to the intake manifold plenum for a more stable vacuum signal

Also available are 2 options for the fuel pressure regulator top color.

Applications

• 2015 - 2021 Subaru WRX STI
• 2008 - 2014 Subaru Impreza WRX STi