JDMSPEED 255LPH High Flow External Inline Fuel Pump — GSL392/400-939 Replacement, All-Metal with Installation Kit

JDMSPEED 255LPH High Flow External Inline Fuel Pump is a universal, high-pressure replacement for GSL392/400-939 that delivers up to 255 liters per hour and supports performance builds up to about 650 HP.

This external inline fuel pump by JDMSPEED is built as a direct-fit performance upgrade or replacement for GSL392 (400-939) style pumps. It arrives as a fully metal-shelled unit with an installation kit that includes barbed fittings, electrical connectors, mounting hardware and cushions so you can mount it outside the tank and tune final pressure with a regulator. The pump is specified for 12V input, rated at 255 LPH, and operates across a broad pressure band when paired with an external regulator.

How does this pump improve fueling on modified engines?

The higher 255 LPH flow gives a larger margin for injectors and fuel delivery on turbocharged or supercharged engines compared with many OEM pumps. It reduces the risk of fuel starvation at high RPM and supports richer fueling for high power applications when combined with proper fuel lines and a regulator.

• 255 liters per hour flow rate for higher-demand systems
• Suitable for turbo, supercharged and heavily modified EFI setups
• All-metal body resists heat and mechanical wear
• Supports fuels including gasoline, pump gas, race gas, diesel, E85 and ethanol

What comes in the installation kit and how easy is fitment?

The included kit contains everything needed to mount and wire the pump for most universal installations outside the tank. Because the kit provides hose barbs, crush washers, electrical connectors, clamps and a mounting cushion, basic mechanical skills and common tools are usually enough for a secure install.

• 1x JDMSPEED GSL392-style external fuel pump
• 2x 3/8" hose barb fittings, 2x crush washers, 2x electrical connectors
• 2x starlock washers, 2x nuts, 2x mounting clamps, 1x mounting cushion
• Mounts externally—final pressure set by a separate regulator

What pressures and fuels are supported, and do I need a regulator?

The pump is capable of operating across a wide pressure range; final system pressure must be controlled by an external regulator. It is compatible with a wide range of fuels, but vehicle wiring and supply voltage will affect delivered flow.

• Operating pressure range: 15–120 PSI (final pressure set via regulator)
• Minimum supply voltage: 12V; voltage affects flow output
• Fuel compatibility: gasoline, pump/race gas, diesel, E85 and ethanol
• Recommended: quality external regulator and proper fuel lines for high-pressure use

Is this pump a direct replacement for GSL392 or will I need modifications?

JDMSPEED designed this unit as a universal GSL392/400-939 style replacement, matching the common form and inlet/outlet positions for inline external installs. Most users will mount it with the supplied clamps and fittings, but verify electrical connections and fuel line sizes to match your vehicle’s layout.

• Replaces part numbers: GSL392-400-939, GSL392400939, GSL392, 400-939
• Universal external mount fits the majority of EFI applications
• All-metal inlet and outlet—use correct hose and clamp sizes
• Check wiring polarity and fusing for safe installation

Who is this for: This JDMSPEED 255LPH external inline pump is aimed at enthusiasts, tuners and mechanics upgrading fuel delivery for higher horsepower naturally aspirated, turbocharged or supercharged engines. It’s appropriate for anyone replacing a failing GSL392-style pump, building a high-flow EFI fuel system, or needing a robust universal external pump that accepts multiple fuel types. Ensure you pair the pump with a proper fuel pressure regulator, correct wiring and compatible fuel lines for safe, reliable operation.