Radium 20-0199 FPD-R Inline Fuel Pulse Damper Kit for -6/-8/-10AN Fuel Lines

Vehicle Fitment

• Universal - compatible with any EFI fuel system using a returnless/FPR-style setup (not compatible with return-style fuel systems)

Fitment Notes

• Sold in multiple variants by fitting size - confirm you select the correct suffix for your fuel line: -01 (5/16 in. barb, hose clamps required), -06 (-6AN adapter fittings), -08 (-8AN adapter fittings), or -10 (-10AN adapter fittings)
• Base static fuel pressure requirement: 40-70 psi (FPD-R Standard Range); higher-pressure applications should use Radium's FPD-XR instead
• Can be mounted at any angle, including upside down; install as close to the fuel rail(s) as practical and away from excessive heat

Features

• Absorbs fuel injector pressure pulses to stabilize fuel rail pressure across the RPM range
• Helps eliminate idle surge and erratic lean AFR spikes ("stumbling"), especially with high-flow injectors
• Vacuum/boost reference port maintains proper damping performance even at elevated fuel pressures on rising-rate FPR setups
• Anodized and laser-engraved aluminum top with anodized aluminum body for corrosion resistance
• Large 0.69 in. center bore with two inline inlet/outlet ports (3/4"-16 UNF, 8AN ORB) for minimal flow restriction
• 1/8 in. NPT female port for a fuel pressure gauge or sensor
• Compatible with all fuel types, including gasoline, E85, and methanol blends
• Includes M6 mounting bolts and nuts
• Compact 1.98 in. height fits space-constrained engine bays

Specifications

• Type: Inline Fuel Pulse Damper (FPD-R)
• Base Static Pressure Range: 40-70 psi
• Housing Ports: 3/4"-16 UNF, 8AN ORB
• Gauge Port: 1/8 in. NPT Female
• Height: 1.98 in.
• Material: Anodized Aluminum
• Fuel Compatibility: Gasoline, E85, Methanol, and Alcohol Blends
• System Compatibility: Returnless/FPR Fuel Systems Only

Included Components

• 1x FPD-R Inline Fuel Pulse Damper
• 1x Set Adapter Fittings (size per variant: -01, -06, -08, or -10)
• 1x Set M6 Mounting Bolts and Nuts

Product Description

The Radium 20-0199 FPD-R is an inline fuel pulse damper designed to absorb the pressure oscillations created every time an injector opens and closes. On upgraded fuel systems - especially those running high-flow injectors - those pulses can destabilize rail pressure, showing up as idle surge or hard-to-tune lean AFR spikes. The FPD-R's internal diaphragm smooths those pulses out across the RPM range.

Unlike many fixed dampers, the FPD-R includes a vacuum/boost reference port, so it keeps working correctly even at elevated fuel pressure on boosted setups running a 1:1 rising-rate fuel pressure regulator. At 1.98 inches tall, it's the more compact option in Radium's lineup (versus the taller FPD-XR), making it a good fit for tight engine bay routing, and it can be mounted in any orientation, including upside down.

Because the fuel line connection varies by build, this damper is sold in several kit variants - a 5/16 in. barb version for rubber hose, or -6AN, -8AN, and -10AN adapter versions for braided line - so be sure to order the variant that matches your fuel line size. It's intended for returnless/FPR-style fuel systems only, not return-style setups, and is safe for use with gasoline, E85, and methanol blends.