





Radium DMR-RA Direct Mount Fuel Pressure Regulator
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Description
Radium DMR-RA Direct Mount Fuel Pressure Regulator
Application: Universal – mounts directly to 8AN ORB fuel rail ports (6AN/10AN ORB with optional unions, or off-rail with 20-0624)
Part Type: Compact adjustable direct-mount fuel pressure regulator (RA-series)
Part Number: 20-1623-00, 20-1623-01
The Radium Direct Mount Regulator (DMR) is a compact, adjustable EFI fuel pressure regulator designed for high-flow fuel systems where space is tight. It mounts directly to an 8AN ORB fuel rail port – such as those on Radium fuel rails – using the included swivelling inlet fitting, or off-rail with the optional remote mount kit.
Pressure is set with a tool-less knob with no jam nut or set screw, and the threads are sealed against vacuum/boost leaks. A single stainless steel return orifice creates laminar flow for improved pressure stability.
Key Features
- Direct Mount: Swivelling inlet fitting mounts the regulator straight onto an 8AN ORB fuel rail port
- Tool-less Adjustment: Knob adjustment with no jam nut or set screw, and no vacuum/boost leaks through the threads
- Stable Pressure: Single stainless steel return orifice for laminar flow
- Vacuum Reference: 360° swivelling, double O-ring sealed port with interchangeable 10-32 threaded fittings
- Gauge Ports: Two 1/8" NPT side ports (plugs included)
- Fuel Compatibility: All gasoline types (unleaded, leaded, oxygenated, pre-mix) and alcohol blends (methanol, ethanol, E85)
Available Configurations
- 20-1623-00: Black
- 20-1623-01: Green
What's Included
- Main rotating assembly
- Swivelling inlet fitting for 8AN ORB fuel rail
- 6AN male 90° swivel for return line
- 5mm barbed vacuum fitting
- 3AN male vacuum fitting
- 1/4" push-to-connect vacuum fitting
- Vacuum plug fitting (returnless systems)
- PTFE-impregnated 1/8" NPT plugs (x2)
Optional Parts
- Radium Engineering 6AN ORB to 6AN ORB Swivel Union (14-0706) – for 6AN ORB fuel rails – replaces the included 8AN fitting
- Radium Engineering 10AN ORB to 6AN ORB Swivel Union (20-1006) – for 10AN ORB fuel rails – replaces the included 8AN fitting
- Radium DMR Direct Mount Regulator Remote Mount Adapter Kit (20-0624) – stainless bracket and inlet fittings for off-rail mounting
- Radium Fuel Pressure Gauge 0-100psi (20-0029) – seals into either 1/8" NPT port
- Radium Fuel Pressure Gauge With 90 Deg Adapter (20-0407) – gauge with 90° 1/8" NPT adapter
- Radium Diaphragm Service Replacement FPR (18-0017) – replacement diaphragm
Important Notes
- Regulator inlet port is 6AN ORB female – the included adapter suits 8AN ORB ports; other port sizes need the optional unions
- Use a medium-strength wicking thread locker on the vacuum fitting and PTFE paste on gauge threads
- The vacuum plug is required for returnless systems
- Maximum pressure depends on the pump relief valve or pump controller maximum current
- A rapid fuel pressure drop after the engine or pump is switched off is normal for aftermarket regulators – pressure resets as soon as the pump is reactivated
- Long cranking or slow pressure build-up is not caused by the regulator – it usually points to the feed line draining back to the tank (e.g. a leaking pump module, venturi jet pump or missing check valve)
- Installation instructions are available in the Instructions tab
Vehicle Fitment
- Universal – any EFI fuel system with an 8AN ORB fuel rail port (6AN/10AN ORB with optional unions, or remote mounted with 20-0624)
Not sure if this suits your vehicle? Email sales@coore.com.au and our team will confirm fitment.

