Spool Stage 1 FX-170 BMW N55 Upgraded High Pressure Fuel Pump

Spool FX-170 BMW N55 Upgraded High Pressure Fuel Pump

What is the FX-170?
The FX-170 is an upgraded high-pressure fuel pump (HPFP) designed for BMW N55-powered 35i single-turbo models. Featuring a larger bore than the stock pump, it delivers approximately 50% more flow, making it ideal for higher performance applications. Fully E85-compatible and 100% plug-and-play, it requires no cutting, splicing, or modifications. The increased flow allows you to run higher ethanol concentrations and provides the fueling necessary to support larger turbos.

Why do you need it?
The stock HPFP on the N55 engine has limited capacity, which becomes a bottleneck when tuning for higher power outputs. The FX-170 solves this problem by offering 50% more flow, enabling you to push the platform further with bigger turbos and higher ethanol blends. Whether you're chasing more power or running advanced fuels, the FX-170 is a critical upgrade for unlocking your engine's potential.

Are tune changes required?
Yes, calibration changes are required to use the upgraded pump. These updates must be applied before starting the engine with the FX-170 installed to prevent potential damage and warranty voids.

Spool Performance can provide calibration details to your existing tuner or help connect you with experienced tuners familiar with these pumps. While Spool Performance does not provide custom tunes, we’re here to assist with any questions your tuner may have. Custom tuning is essential to maximize the performance of your upgraded fuel system based on your specific setup and conditions.

Low-Pressure Fuel Pump Upgrade
Proper low-pressure fueling is crucial to the performance and longevity of the HPFP and injectors in direct injection (DI) systems. Insufficient low-pressure fueling can cause damage to the HPFP piston and bore, which rely on fuel for lubrication. Any damage caused by low-pressure starvation is detectable and will void the warranty.

To avoid these issues, ensure your fuel system includes adequate low-pressure upgrades where needed. Carefully plan your build to include a robust low-pressure system that complements the FX-170 for reliable, high-performance operation.