Radium Engineering FPD-R Inline Fuel Pulse Damper

Stabilize Fuel Pressure and Eliminate Lean Stumble with the Radium Engineering Inline Fuel Pulse Damper

The Radium Engineering RAD20-0199 FPD-R Inline Fuel Pulse Damper is a precision-engineered fuel system component that absorbs the pressure oscillations created by sequential fuel injector opening and closing events in performance fuel systems. The RAD20-0199 uses 8AN ORB port connections with an FKM O-ring seal for inline installation into any fuel line, housing an internal diaphragm calibrated for a base static fuel pressure range of 40-70 PSI (FPD-R Standard Range). A vacuum/boost reference port on the RAD20-0199 allows it to function correctly at elevated fuel pressures in boosted systems with rising-rate fuel pressure regulators, maintaining consistent damping performance regardless of boost level. The result is a measurable stabilization of fuel rail pressure across the RPM range, solving lean stumble, erratic AFR spikes, and idle surge commonly seen in upgraded fuel systems , particularly with high-flow injectors on batch injection setups. Safe for use with all fuel types including E85.

Key Features

• Absorbs injector-generated pressure pulses to stabilize fuel rail pressure across the entire RPM range
• 8AN ORB port connections seal with FKM O-rings for a leak-free inline fuel line installation
• Vacuum/boost reference port enables correct operation in boosted rising-rate FPR systems at varying boost levels
• FPD-R Standard Range: 40-70 PSI base static fuel pressure , suitable for most naturally aspirated and boosted applications
• Anodized and laser-engraved aluminum top with anodized aluminum body , corrosion resistant and fuel safe
• Compatible with all fuel types including gasoline, E85, methanol, and alcohol blends
• Can be mounted at any angle including upside down , installation flexibility for tight engine bay routing
• RAD20-0199 is not compatible with return-style fuel systems , for returnless/FPR systems only

Specifications

What's Included

• 1x RAD20-0199 Radium Engineering FPD-R Inline Fuel Pulse Damper
• Vacuum/boost reference port fitting
• Installation instructions

Frequently Asked Questions

The RAD20-0199 absorbs fuel pressure oscillations caused by injectors rapidly opening and closing. In upgraded fuel systems with high-flow injectors, these pulses can destabilize fuel rail pressure enough to cause lean stumble, erratic AFR readings, and rough idle. The RAD20-0199 damps those pulses for more consistent fuel delivery and improved drivability.

The RAD20-0199 uses 8AN ORB (O-Ring Boss) port connections on both the inlet and outlet. Use 8AN fittings with FKM O-rings for a leak-free connection. The ORB port is a standard connection type used throughout performance fuel system plumbing.

Yes. The RAD20-0199 is compatible with gasoline, E85, methanol, and other alcohol-based fuels. The FKM O-ring seals are specifically chosen for chemical resistance to ethanol and methanol blends.

No. The RAD20-0199 is designed for returnless or FPR-regulated fuel systems only. Do not install it in a traditional return-style fuel system with a separate return line to the tank.

The RAD20-0199 FPD-R Standard Range is calibrated for 40-70 PSI base static fuel pressure. This covers the vast majority of naturally aspirated and turbocharged performance applications running common fuel pressure regulators. For systems outside this range, contact Radium Engineering for alternative models.

Yes. The vacuum/boost reference port on the RAD20-0199 allows it to maintain correct diaphragm function at elevated fuel pressures in boosted applications with a rising-rate FPR. Connect the reference port to the intake manifold boost/vacuum source for proper rising-rate operation.

Install the RAD20-0199 as close to the fuel rail inlet as possible for maximum effectiveness. It should be installed inline on the fuel feed line between the fuel pressure regulator outlet and the fuel rail inlet.

The RAD20-0199 is a Radium Engineering USA-made product. Contact Radium Engineering directly for warranty terms and support for this product.

Installation Notes

1. Relieve fuel system pressure before disconnecting any fuel lines
2. Identify the fuel feed line between the fuel pressure regulator outlet and the fuel rail inlet
3. Install 8AN ORB fittings and compatible fuel line to connect the RAD20-0199 inline at the chosen location
4. Connect the vacuum/boost reference port to a manifold vacuum/boost source using the included fitting and suitable vacuum hose
5. Tighten all 8AN ORB fittings to spec , do not overtighten the aluminum body ports
6. Inspect all connections for leaks before and after the first start
7. Run the engine and confirm fuel pressure stability on a gauge before driving

WARNING: This product can expose you to chemicals including lead and phthalates, which are known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.