This fuel pressure regulator (FPR) and fuel filter is a bolt-in kit designed specifically for the 2001-2006 BMW (E46) M3 using factory fuel lines. The OEM fuel filter is replaced with a high-flow Radium Engineering fuel filter. The filter is compatible with all fuel types.

The OEM regulator is replaced with a Radium Multi-Port FPR. The RA-series regulators feature the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased. To aid in adjusting pressure, there are incremental detents that provide haptic feedback to the user. Every detent permits 1psi (+/-0.5psi) of adjustment depending on current fuel pressure.

The RA-series regulators feature a 360 degree swiveling vacuum reference port that is double O-ring sealed. This is the first in the industry. It permits the installer to quickly point the vacuum fitting in any direction with no tools required.

There are 4 interchangeable #10-32 threaded vacuum port fittings provided to cover all scenarios.

• Barbed Fitting: A black zinc-plated 3/16" (5mm) barb machined from high strength steel that is compatible with the following vacuum hoses: 5/32" (4mm), 3/16" (5mm), and 7/32" (6mm).
• 3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends.
• Push-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1/4" OD tubing.
• Vacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure.

This kit is suitable with all gasoline types including unleaded, leaded, oxygenated, and pre-mixes. Furthermore, it is compatible with alcohol blends of fuel including methanol, ethanol, and E85.

ABOUT FUEL PRESSURE DROP AFTER SHUTOFF

Some installations may experience a rapid fall of fuel pressure when the engine and/or fuel pump shuts off. This is considered normal operation for aftermarket fuel pressure regulators, regardless of brand. 

This can occur due to the diaphragm seat and the return orifice not fully sealing when fuel flow is stopped. For regulators to have the ability to regulate high fuel flow rates, the size of these components must be increased. This creates larger sealing surfaces between the components, preventing them from forming a perfect seal, even with high spring rates. This is not an indication of an issue or defect and it is not a cause for concern on its own.

You do NOT need to contact technical support about this issue.

Fuel pressure will reset immediately when the fuel pump is activated again.

If the engine is experiencing other symptoms such as long cranking to start, or delays in pressure building when cranking, these symptoms are unrelated to the regulator. There is likely an issue with the fuel feed hose draining back to the tank. This is most likely due to an internal leak somewhere in the pump module: possibly a venturi jet pump, or the lack of a fuel pump check valve.

• Multi-port regulator
• High flow fuel filter
• Fuel pressure gauge
• Necessary fittings for installation