Radium Engineering FPD-XR Inline 6AN Fuel Pulse Damper

Have you ever noticed how the opening and closing of fuel injectors can create those pesky pressure pulses in your fuel rail? These fluctuations can lead to unstable fuel pressure, which is not ideal for your engine's performance. That's where a fuel pulse damper (FPD) comes into play. This nifty device features an internal diaphragm that absorbs those oscillating pulses, helping to stabilize fuel pressure. You'll find that this correction can be felt across the RPM range, making a real difference in idle surge, particularly when using high-flow injectors. Plus, if you've experienced erratic lean air/fuel ratio spikes'often referred to as "stumbling"'the FPD can help smooth things out, making tuning a lot easier.

Compatibility with High-Performance Engines

Many high-performance OEM engines, like the Toyota 2JZ-GTE, Nissan VQ35DE, and Subaru EJ20/EJ25, come equipped with an in-line fuel pulse damper straight from the factory. This makes the FPD-XR a fantastic choice for applications where direct fuel rail mounting just isn't an option.

Designed for Flexibility and Performance

Radium Engineering has designed the FPD to be incredibly versatile. It features a vacuum/boost reference port, ensuring that the fuel pulse damper performs optimally even under elevated fuel pressures. This is particularly crucial for boosted systems that rely on a 1:1 rising rate fuel pressure regulator.

Size Matters

The FPD-R (green top) stands at 1.98" tall, making it a bit shorter than the 2.60" FPD-XR (black top). If you're working with space constraints, the FPD-R might be your go-to. However, if you have the room, Radium recommends the FPD-XR for its wider response range, ensuring you get the best performance possible.

Base Pressure Requirements

Both the FPD-R and FPD-XR have specific base "static" fuel pressure requirements:

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

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

Important Note

• The ranges mentioned above are for base static fuel pressures only. Any dynamic fuel pressure created by a rising-rate FPR outside of these ranges is acceptable, provided the base "static" fuel pressure is set within these limits and the vacuum/boost reference line is connected.

Key Features

• The kit boasts an anodized aluminum housing with a generous 0.69" center bore, featuring two in-line inlet/outlet ports machined with 3/4"-16 UNF threads for 8AN ORB fittings. Choose from three kits that include different male adapter fittings (-6AN, -8AN, barb) based on your fuel feed hose size. These fittings seal securely to the billet housing using FKM O-rings.
• A 1/8" NPT female port is conveniently threaded into the center of the fuel pulse damper, perfect for attaching a fuel pressure gauge or other sensors for pressure or temperature data.
• Thanks to the supplied M6 bolts and nuts, you can mount the FPD kit at any angle'even upside down! For optimal results, plumbing the damper as close to the fuel rail(s) as possible is recommended. Just remember to keep it away from areas that experience excessive heat.
• This product is compatible with all fuel types, including alcohol blends like E85.

Fitting Options

• The inline dampers come in three different versions, allowing you to select based on your hose connection needs.
• The -01 version is ideal for those using 5/16" rubber fuel hoses (hose clamps required).
• The -06 version includes adapter fittings for connecting -6AN hoses.
• The -08 version includes adapter fittings for connecting -8AN hoses.