Spool FX-350 HPFP Kit AMG [M177]

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• You must return the ordered products within 14 days of receiving
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• Commission fee for handling returns is 21,90€
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Return address: QT Parts, Vasarakatu 8B, 37150 Nokia, Finland.

Pre order / made-to-order products

If the product you have ordered is a pre order or made-to-order item, it is not subject to the 14-day right of withdrawal or return under consumer protection laws, as the product is manufactured or sourced specifically based on the customer’s individual order.

If you wish to cancel your order before receiving the product, we will refund 50% of the total order amount.

This condition applies to the following product categories:

• Suspension
• Engine Tuning
• Engine Parts
• Exhaust Systems
• Fueling
• Turbochargers/superchargers
• Drivetrain
• ECE-approved Downpipes

All of the above products are manufactured or sourced individually based on the customer’s order, and therefore cannot be returned after delivery, unless the product has a manufacturing or material defect.

In the event of such a defect, the standard liability for defects as provided by consumer protection legislation shall apply.

Spool FX-350 HPFP Kit | AMG M177

The Spool Performance FX-350 is the next-generation high-pressure fuel pump (HPFP) upgrade for Mercedes-AMG M177 engines. This model surpasses the previous FX-200 in performance and efficiency, offering significantly higher pressure and better fuel utilization for high-power applications.

What is the FX-350?

The FX-350 is an advanced HPFP designed to operate at significantly higher pressures than traditional solutions.

• Operating pressure up to 35 MPa / 350 bar
• Up to +90% more flow compared to stock
• Full E85 compatibility
• Plug & Play installation without modifications

Effects of higher pressure:

• Up to approx. 40% more fuel through the injectors before reaching injection limits
• Improved fuel atomization
• More efficient combustion and better efficiency
• Enables higher power and better response

Why is an upgrade necessary?

The M177 engine's stock HPFP limits performance during tuning:

• Insufficient fuel capacity for high power levels
• Ethanol blends remain limited

The FX-350:

• Significantly increases fuel system capacity
• Enables larger turbos and more aggressive tunes
• Greatly expands the platform's performance potential

Package contents

• 2 x FX-350 high-pressure fuel pumps
• Upgraded fuel lines + installation hardware
• Bosch 10 micron high flow fuel filter
• Ethanol content monitoring system (optional, with mobile app)

Spool 10-micron filter

• Excellent filtration performance without significant pressure drop
• Protects the pump and injectors from contaminants
• Optimized for the Mercedes platform

Spool Ethanol Content Monitor (optional)

• Real-time ethanol content and fuel temperature display
• BLE 4.0 connection to mobile app
• Enables precise mixture ratio control
• PTFE-lined, braided stainless steel E85-compatible fuel lines

Software requirements

• Requires software modifications before commissioning
• Calibration is essential for performance and safety

Spool:

• Provides the necessary data to the tuner
• Assists in finding an experienced tuner if needed

Note: Spool does not offer ready-made custom tunes

Important note: LPFP

The low-pressure fuel system is critical:

• Insufficient supply can cause damage to the pump and injectors
• HPFP lubrication is based on fuel flow
• Lack of fuel can lead to wear and failure

Recommendation: ensure adequate low-pressure side upgrade