The opening and closing of fuel injectors creates pressure pulses in the fuel rail which 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.
Many high performance OEM engines use an in-line fuel pulse damper from the factory including the Toyota 2JZ-GTE, Nissan VQ35DE, and Subaru EJ20/EJ25. The use of an inline damper is great for applications where there is not an option for direct fuel rail mounting.
What makes Radium FPDs unique?
Along with having the flexibilty 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?
At 1.98″ tall, the FPD-R (green top) is slightly shorter than the 2.60″ FPD-XR (black top) allowing it to be used in space-contrained applications.
Which damper do 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 – 120psi (static)
Base pressure is the fuel pressure measured when the fuel pump is running WITHOUT a vacuum line connected to the regulator.
-Anodized/laser engraved aluminum top, R=range or XR=extra range
-Anodized aluminum body threaded for 8AN ORB
-Anodized aluminum ORB adapter fittings, selectable size
-Gasoline and alcohol (E85) resistant diaphragm
-Stainless steel M6 mounting bolts and nuts
-Rubber vacuum hose, 4mm ID
-Vacuum hose Y-fitting
-1/8″ NPT plug