BMW F-Series N55 N20 Stage 3.5 LPFP Upgrade - Walbro 450 + 535 - 950 WHP

Take your BMW F-Series N55 or N20 to the next level with the OneFastShop Stage 3.5 Dual Walbro 450 + 535 Low Pressure Fuel Pump (LPFP) assembly. Designed for high-boost, ethanol-based, and port-injected builds, this complete plug-and-play LPFP upgrade delivers the fuel volume required to support up to 950 WHP on pump gas or 875 WHP on full E85. Direct replacement for BMW OEM part #16117243975.

The dual pump system pairs a Walbro F90000274 450LPH primary pump with a Walbro F90000295 535LPH secondary pump and includes a boost-referenced pressure switch (Hobbs switch) for automatic secondary pump activation. Arrives fully pre-assembled with all wiring, fittings, and hardware pre-configured - no splicing, cutting, or crimping required. Compatible with Reflex and Pro EFI controllers, and suitable for stock or heavily modified applications.

Key Features

• Supports up to 950 WHP on pump gas / 875 WHP on E85
• Dual pump assembly: 1x Walbro 450LPH (F90000274) + 1x Walbro 535LPH (F90000295)
• Boost-referenced pressure switch (Hobbs switch) for automatic secondary pump activation
• 100% plug-and-play - no wiring modifications, splicing, or cutting required
• Complete OEM-replacement fuel bucket with top hat and float assembly
• E85-compatible for ethanol and flex-fuel builds
• Compatible with Reflex and Pro EFI controllers
• Suitable for port injection and upgraded turbo setups
• Direct replacement for BMW OEM #16117243975

Fitment

Specifications

What's in the Box

• 1x Walbro 450 fuel pump (F90000274)
• 1x Walbro 535 fuel pump (F90000295)
• Complete replacement fuel bucket with top hat and float
• Boost-referenced pressure switch (Hobbs switch)
• Positive and negative trigger wiring harnesses
• BMW secondary fuel pump activation harness
• In-tank filters, fittings, O-ring, and test plug