Radium Engineering DFPR (Dual Fuel Pressure Regulator) – Universal

The Radium Engineering DFPR (Dual Fuel Pressure Regulator) is a unique solution for vehicles running both direct injection (DI) and port injection (PI) fuel systems. Designed to allow independent pressure control for each circuit, the DFPR streamlines complex plumbing and eliminates pressure spikes caused by mechanical high-pressure fuel pumps (HPFP). It enables precise fuel delivery and smooth performance under all conditions.

Key Features:

• Independent pressure control for direct injection (FPR1) and port injection (FPR2)
• Single fuel inlet shared between both systems
• Tool-less pressure adjustment with tactile detents (1 psi per increment)
• Integrated stainless return orifice for stable, laminar fuel flow
• Dual 1/8" NPT sensor ports for monitoring FPR1 and FPR2 independently
• Vacuum-referenced 1:1 pressure control with full adjustability
• Suppresses HPFP-induced pressure spikes for improved system longevity

Plumbing Overview:

• Pump In: 8AN ORB (3/4-16") – connect from LPFP (low pressure fuel pump)
• FPR1 Out: 8AN ORB – to high-pressure fuel pump (HPFP)
• FPR2 Out: 8AN ORB – to port injection fuel rail(s), or plug if unused
• Return: 8AN ORB – return to fuel tank or filler pipe
• Auxiliary Ports: (2x) 1/8" NPT – for sensors or fuel pressure gauge

Vacuum Reference Options (Included):

• 3/16" barbed fitting – compatible with 5/32", 3/16", or 7/32" vacuum hose
• 3AN male fitting – for braided vacuum lines
• Push-to-connect – for 1/4" OD hard plastic tubing
• Vacuum plug – for returnless or constant pressure applications

Fuel Pressure Range:

• Minimum: 18.5 psi (1.3 bar)
• Maximum: Dependent on fuel pump system – regulator is not internally limited
• Note: FPR2 pressure will always be ≤ FPR1

Mounting & Installation:

• Includes anodised aluminium bracket and M6 stainless flush-mount hardware
• Compact design allows easy integration in engine bays or bulkhead locations

Fuel Compatibility:

• Compatible with all gasoline types: unleaded, leaded, oxygenated
• Fully supports methanol, ethanol, and E85 blends

Included Components:

• DFPR main rotating assembly
• Mounting bracket with stainless hardware
• (2) Barbed vacuum fittings
• (2) Push-to-connect vacuum fittings
• (2) 3AN male vacuum fittings
• (2) Vacuum plug fittings
• (4) 8AN ORB to 6AN male fittings
• (4) 8AN ORB to 8AN male fittings
• (1) 8AN ORB plug

Ideal for turbocharged and high-horsepower vehicles using hybrid fuel systems, the DFPR allows for complete control of both DI and PI pressure targets from one compact unit. Designed with precision adjustment, stability, and fuel compatibility in mind, it’s the ultimate regulator for dual-fuel strategies.