Radium Engineering FPD-R Direct Mount 8AN ORB Fuel Pulse Damper Kit | 20-0776 Radium Engineering

Applications:

This item is non application specific. Please verify compatibility before purchase. May require some modification for proper installation.

Features:

The opening and closing of fuel injectors creates pressure pulses in the fuel rail; this can lead to unstable fuel pressure. In order to achieve a safe and consistent rail pressure, a fuel pulse damper (FPD) is often necessary.

The FPD’s internal diaphragm will absorb oscillating pulses and stabilize fuel pressure. This correction can be measured throughout the RPM range and can often help idle surge, especially with high flow injectors. Furthermore, a fuel pulse damper can help solve erratic lean air/fuel ratio spikes, commonly experienced as “stumbling”, that are difficult to tune out.

Fuel pulse dampers can be mounted at any angle, including upside down. There are many variables that dictate if a fuel system requires fuel pulse dampers. For instance, there are cases where multiple dampers are necessary. There are also other times when the fuel system benefits with a fuel pulse damper on the return line.

Note: NOT TO BE USED ON THE LOW PRESSURE SIDE OF MECHANICAL FUEL PUMPS (INCLUDING DIRECT INJECTION ENGINES).

Key features:

• Vacuum Reference Disconnected: 40-70 psi
• Vacuum Reference Connected: No psi limit
• Mating Male Threads: 8AN ORB
• Mating O-ring Material: FKM
• Swivel/Indexing Capable: Yes
• Vacuum Port Orientation: Even after tightened, the newest 8AN ORB dampers will swivel, permitting the vacuum port to be clocked 360 degrees.
• This product is safe for use with all fuel types including alcohol blends such as E85.

IMPORTANT: The ranges above are base static fuel pressures only. Any dynamic fuel pressure created by a rising-rate FPR outside of this range is acceptable, but only when the base “static” fuel pressure is set within these ranges and the vacuum/boost reference line is connected.

What’s included?

• Anodized and laser engraved aluminum top, R=range
• Anodized aluminum body with 8AN ORB male threads
• Stainless steel hardware
• Rubber vacuum hose, 4mm ID
• Vacuum hose Y-fitting

More Information:

What makes Radium FPDs unique?

Along with having the flexibility of using common fittings, Radium Engineering FPD’s use a vacuum/boost reference port which allows for proper fuel pulse damper performance even at elevated fuel pressures. This becomes essential for boosted systems that use a 1:1 rising rate fuel pressure regulator.

What is the difference between FPD-R and FPD-XR?

The FPD-R (green top) is slightly shorter than the FPD-XR (black top) allowing it to be used in space-constrained applications.

Which Damper should I choose?

The FPD-R (Fuel Pulse Damper-Range) and FPD-XR (Fuel Pulse Damper-Extra Range) both have unique base “static” fuel pressure requirements:

• FPD-R base pressure requirement = 40 – 70psi (static)
• FPD-XR base pressure requirement = 40 – 105psi (static)

Base pressure is the fuel pressure measured when the fuel pump is running WITHOUT a vacuum line connected to the regulator.

Applications Examples: FPD-R vs FPD-XR

Example 1:
Vehicle: Mitsubishi EVO
OEM Base Static Fuel Pressure: 43.5psi
Boost Pressure: 30psi
Rising Rate Pressure Regulator? Yes
Can I use a FPD-R? Yes. Even though fuel pressure is 73.5psi at full boost, the FPD-R will work because the base static pressure was set within the 40-70psi requirement. However, the vacuum/boost reference line must be installed.
Can I use a FPD-XR? Yes. Also, the vacuum/boost reference line does not need to be installed since maximum fuel pressure does not exceed 105psi.

Example 2:
Vehicle: BMW E46 M3
OEM Base Static Fuel Pressure: 72.5psi
Boost Pressure: 20psi
Rising Rate Pressure Regulator? Yes
Can I use a FPD-R? No. Base static fuel pressure exceeds the 40-70psi requirement.
Can I use a FPD-XR? Yes. Also, the vacuum/boost reference line does not need to be installed since maximum fuel pressure does not exceed 105psi.