Radium Engineering DMR-RA (Direct Mount Regulator) Fuel Pressure Regulator Black ORB-8

The DMR features a compact, versatile design that mounts directly to any 8AN ORB fuel rail using the included 360° swiveling adapter. For rails without an 8AN ORB port, Other swivel adapters are available but sold separately. 

Includes:

• Main Rotating Assembly
• 5mm Barbed Vacuum Fitting
• Vacuum Plug Fitting (Returnless)
• 1/4' Push-To-Connect Vacuum Fitting
• 3AN Male Vacuum Fitting
• 6AN Male Swivel (for Return Line)
• Swiveling Inlet Fitting (for 8AN ORB Fuel Rail)
• PTFE Impregenated 1/8' NPT Plugs (x2)

Plumbing:

• Main inlet: 6AN ORB female thread with included swiveling 8AN adapter
• Return port: 6AN ORB with 90° swivel 6AN male fitting
• Two 1/8" NPT ports for pressure gauges, sensors, or plugs (included)

Fuel Pressure Adjustment:
RA-series regulators feature the industry’s first tool-less pressure adjustment knob—no jam nut or set screw required. Turning the knob increases or decreases pressure with no vacuum leaks.

1:1 Rising Rate Vacuum Reference:
A 360° swiveling, double O-ring sealed vacuum port allows tool-free orientation. Includes four interchangeable 10-32 fittings:

• 3/16" (5mm) barbed fitting
• 3AN male fitting
• 1/4" push-to-connect fitting
• Vacuum plug for constant pressure (used in returnless systems)

Fuel Pressure Stability:
A redesigned stainless steel return orifice ensures laminar flow and consistent pressure.

• Minimum pressure: 18.5 psi (1.3 bar)
• Maximum pressure: Determined by fuel pump system limits

Fuel Pressure Drop After Shutoff:
A slight drop in pressure after shutdown is normal due to internal sealing characteristics and is not a defect. Pressure resets once the fuel pump activates.

Fuel Compatibility:
Suitable for all gasoline types (unleaded, leaded, oxygenated, pre-mix) and alcohol blends including methanol, ethanol, and E85.

Installation Instructions