Radium FPR-D Fuel Pressure Regulator Damper | Universal (20-1528-01)

Two parts in one body, which is one less component and one less set of fittings.

The Radium Engineering FPR-D fuel pressure regulator damper consolidates a fully adjustable high performance EFI fuel pressure regulator with a built-in fuel pulse damper into a single high flow package. The damper smooths the noisy fuel systems that suffer pulsing from injectors opening and closing and from the pump itself.

What You'll Feel

• Stable rail pressure without plumbing a separate damper
• Pressure set by hand on the knob, no tools
• Mounting in any orientation, including upside down
• A vacuum port that swivels 360 degrees to point wherever you need

Features

• RA-series adjustable regulator with integrated pulse damper
• Single stainless steel return orifice generating laminar flow for stability control
• 10AN ORB (7/8in-14) inlet (side) and outlet (bottom) ports
• 1/8in NPT auxiliary port for a pressure gauge, with plug included
• Two M6x1mm threaded mounting holes plus laser cut anodized mounting plate
• 360 degree swiveling vacuum reference port, double O-ring sealed
• Minimum pressure 18.5psi (1.3bar); maximum limited by your pump's relief valve or controller
• Green anodized adjustment knob
• Suits all gasoline types plus methanol, ethanol, and E85

The Details

Check your plumbing before ordering: the FPR-D cannot be used in a dead-head fuel system. It has a single inlet and a single outlet (return) port, so it must be plumbed after the fuel rail. If your system dead-heads at the rail, the Radium MPR multi-port regulator is the part you want instead.

The integrated damper works best with a base static pressure of 40 to 105psi, measured with the pump running and no vacuum line connected. Dynamic pressure outside that range is fine provided the vacuum and boost reference line is connected; otherwise that reference is usually plugged.

Four interchangeable 10-32 vacuum fittings are supplied: a 5mm barb suiting 4mm, 5mm, and 6mm vacuum hose; a 3AN male adapter; a 1/4in push-to-connect for hard plastic tubing; and a vacuum plug for maintaining constant non-dynamic pressure, which is what returnless systems need. Radium recommends a wicking medium-strength thread locker when fitting the vacuum fitting.

One thing worth knowing before you call anyone: a rapid drop in fuel pressure after shutoff is normal for aftermarket regulators of any brand, because large sealing surfaces cannot seal perfectly at rest. Pressure resets as soon as the pump runs. Long cranking or delayed pressure build is a different problem, usually the feed hose draining back to the tank through a pump module leak or a missing check valve.

Kit Includes

• Main rotating assembly with damper
• Mounting bracket with M6x1mm hardware
• 5mm barbed vacuum fittings (x2), vacuum plug fittings (x2), 1/4in push-to-connect fittings (x2), 3AN male vacuum fittings (x2)
• 6AN male adapters (x2) and 8AN male adapters (x2)
• 1/8in NPT port plug
• Vacuum hose Y-adapter and 5/32in ID vacuum hose

Applications

• Universal, any EFI fuel system with a return line

Important Notes

• Cannot be used in a dead-head fuel system; must be plumbed after the fuel rail. Use the MPR for dead-head plumbing.
• Dampers CANNOT be used with mechanical fuel pumps or direct injection. Those create pressure pulses too strong for the diaphragm and will rupture it in short order.
• Damper base static pressure requirement: 40 to 105psi
• Use a wicking medium-strength thread locker on the vacuum fitting