In-line Fuel Pulse Damper, FPD70si AN-10

Nuke Performance In-line Fuel Pulse Damper FPD70si with AN-10 ORB connections, engineered for stable fuel pressure. Standard pressure range, 40-70 PSI.

Modern EFI fuel systems generate high-frequency pressure pulsations during injector operation. The Nuke Performance In-line Fuel Pulse Damper (FPD) is engineered to reduce these pulsations, creating smoother fuel pressure and more consistent fuel delivery.

 FPD70si, for standard pressure range, 40-70 PSI
 Oversized inline AN-10 ORB design for easy integration
 Integrated 1/8 NPT port for additional sensor or gauge
 Reduces high-frequency pressure pulsations
 Safe for all types of fuels, including alcoholic fuels such as E85
 Vacuum / boost reference capable

Designed for EFI fuel systems operating with a base fuel pressure between 40 and 70 PSI, the FPD70si combines a precision billet aluminum body with an optimized diaphragm and spring assembly. The in-line AN-10 ORB layout allows installation directly in the fuel feed line, while the integrated 1/8 NPT port provides a convenient location for a pressure sensor, transducer or mechanical gauge.

 What is a fuel pulse damper, and how does it work?
Every time a fuel injector opens and closes, it generates a small pressure pulse within the fuel system. Individually, these pulses are insignificant, but together they create high-frequency pressure fluctuations that travel throughout the fuel rail and fuel lines. Although often too rapid to appear on a conventional fuel pressure gauge, they can still influence fuel pressure stability, particularly in high-performance EFI systems using large injectors and high-flow fuel pumps.

A Fuel Pulse Damper is designed to absorb these pressure fluctuations before they propagate through the fuel system. Using an internal diaphragm, the FPD smooths pressure variations, contributing to more stable fuel pressure, more consistent fuel delivery, and a fuel system that is easier to calibrate and tune.

 How do I choose the right fuel pulse damper for my fuel system setup?
Choosing the correct Fuel Pulse Damper starts with one measurement: your base fuel pressure. Base fuel pressure is measured with the fuel pump running and the vacuum hose disconnected from the fuel pressure regulator.

FPD70si Standard Pressure Range In-line Fuel Pulse Damper
If your measured base fuel pressure is between 40 and 70 PSI, the FPD70si Standard Pressure Range is the recommended choice for most EFI fuel systems requiring an in-line installation.

FPD110xi Extended Pressure Range In-line Fuel Pulse Damper
If your base fuel pressure exceeds 70 PSI, choose the FPD110xi Extended Pressure Range (available here), engineered for fuel systems requiring operation beyond the Standard Pressure Range.

Both versions feature integrated vacuum/boost reference capability, allowing the diaphragm to remain correctly positioned as fuel pressure changes during engine operation. This keeps the diaphragm operating within its intended working range and provides consistent damping performance across a wider pressure window.

 Why use the vacuum/boost reference on a fuel pulse damper?
The integrated vacuum/boost reference keeps the diaphragm correctly positioned as fuel pressure changes during engine operation, ensuring consistent damping performance over a wider pressure range.

 Optional vacuum/boost reference with the integrated port
 5mm barb fitting and block-off plug included with all dampers

Every Fuel Pulse Damper includes a 5 mm vacuum hose barb and a block-off plug for installations where vacuum/boost reference is not required. For customers preferring hard plastic tubing, the optional Quick Connect to 6 mm tubing (available here) provides a clean and secure quick-connect solution.
M5 Pneufit Quick Connect to 6 mm tubing Part # : 122-10-001

 Where should an In-line Fuel Pulse Damper be installed?
For maximum effectiveness, a Fuel Pulse Damper should be installed as close to the fuel injectors as possible, since this is where the pressure pulsations originate. The In-line Fuel Pulse Damper is designed for fuel systems where direct mounting on the fuel rail is not possible or where an in-line installation is preferred.

 AN-10 ORB in-line design for high-flow fuel systems
 Integrated 1/8 NPT port for pressure sensor, transducer, or gauge

Installed close to the fuel rail, the in-line version provides an effective alternative to direct-mount dampers while allowing flexible placement in the fuel feed line. With AN-10 ORB connections on both ends, it integrates cleanly into high-performance fuel systems without creating an unnecessary flow restriction.
AN-10 ORB to AN-6 Male Part # : 700-04-108
AN-10 ORB to AN-8 Male Part # : 700-04-109
AN-10 ORB to AN-10 Male Part # : 700-04-110

 Why choose the Nuke Performance in-line fuel pulse damper?
The Nuke Performance In-line Fuel Pulse Damper is available in two dedicated pressure ranges, Standard Pressure Range (40–70 PSI) and Extended Pressure Range (40–110 PSI), allowing the diaphragm and spring assembly to operate within the correct working range for different fuel system configurations.

Combined with integrated vacuum/boost reference capability, AN-10 ORB in-line connections, an integrated 1/8 NPT sensor port, and precision CNC-machined billet aluminum construction, every In-line Fuel Pulse Damper is purpose-built for installations where stable fuel pressure and flexible placement are equally important.

There is no substitute for the quality of Nuke Performance.

 Fuel Pulse Damper, FPD70si AN-10 Specifications:
For more information about specifications, view the product manual.

 Download Product Sheet (.pdf)

 Fuel Pulse Damper, FPD70si includes:
1 x FPD70si fuel pulse damper
1 x M5 to 5mm barb vacuum fitting
1 x K6S M5x6mm stainless steel block-off bolt
1 x 1/8 NPT plug
1 x Stainless steel bracket