Spool Performance FX-350 Upgraded High Pressure Fuel Pump System | GLS63 AMG [M177]

Push the performance envelope of your Mercedes-AMG GLS63 with the Spool Performance FX-350 High-Pressure Fuel Pump (HPFP) System—the most advanced HPFP upgrade available for the M177 engine. Designed to outperform both OEM and previous FX-200 systems, the FX-350 provides unmatched fuel delivery, pressure, and atomization to support serious horsepower builds and high ethanol blends.

What is the FX-350?

The FX-350 is Spool Performance’s most powerful high-pressure fuel pump upgrade to date, engineered to operate at 35Mpa of pressure—a 40% increase in injector fuel flow over previous models. With nearly 90% more flow capacity than the factory pump, the FX-350 enables your direct injection system to keep up with bigger turbos, aggressive tunes, and high ethanol content without compromise.

Key Performance Benefits:

• 90% Increased Fuel Flow vs. Stock

• Supports Higher Ethanol Content (E85-Compatible)

• Delivers 35Mpa of Fuel Pressure for Superior Flow

• Improves Fuel Atomization for Enhanced Combustion Efficiency

• Boosts Power, Fuel Economy, and Reduces Emissions

Complete Plug-and-Play Kit Includes:

• 2 x FX-350 High-Pressure Fuel Pumps

• 1 x Bosch-Spec 10-Micron High-Flow Fuel Filter

• 1 x Ethanol Content Monitor Kit (optional, includes mobile app support)

• Upgraded Braided Steel PTFE Fuel Lines (E85-safe)

• All Required Installation Hardware

Spool 10-Micron Filter Unit:

The included Bosch-spec 10-micron filter ensures top-tier filtration with no measurable pressure drop, protecting your high-pressure fuel pumps and injectors from debris. This is a must-have addition for reliability and performance.

Spool Ethanol Content Monitor (Optional):

Monitor your in-tank ethanol content and fuel temperature with Spool’s BLE 4.0-enabled ECA module. Integrated mobile app support provides real-time readouts without interrupting other Bluetooth functions. Includes a 0-5V analog output for flex-fuel tuning if needed.

Tune Required for Optimal Performance:

Calibration adjustments are required to run the FX-350 safely and effectively. Spool Performance provides calibration data to your tuner or can assist in connecting you with trusted tuning professionals. Starting the engine without proper tuning will void the warranty.

Low Pressure Fuel System Support is Critical:

High-performance HPFPs like the FX-350 rely on adequate low-pressure fuel delivery. Inadequate flow or pressure can cause internal wear or failure. Upgrading your low-pressure fuel pump (such as the Spool Stage 3 LPFP) is highly recommended when installing this system.

Take Your M177 Build to the Next Level

If you’re serious about horsepower and ethanol performance, the Spool FX-350 HPFP system is a vital component for safely and efficiently fueling your Mercedes-AMG GLS63 M177. Precision-engineered for enthusiasts who demand the best.

Note: 'New' merchandise may be returned for exchange or refund within 15 days from the date of shipment. 'New' merchandise must be unused and free from installation or mounting damage. Installation or modification of parts waives your right to returns, refunds, or exchanges.