Spool Performance FX-350 High-Pressure Fuel Pump Upgrade for Audi RS Q8 

What is the FX-350?

The FX-350 is a high-performance mechanical high-pressure fuel pump designed to elevate the capabilities of your Audi RS Q8. Featuring a larger bore size than the stock pump, it provides approximately 90% more fuel flow, making it ideal for performance tuning and upgrades. Fully E85 compatible and plug-and-play, the FX-350 requires no cutting or splicing during installation. This increased fuel flow allows for higher ethanol concentrations and supports larger turbos, making it perfect for drivers seeking maximum performance. Additionally, the FX-350 operates at pressures up to 350 bar, boosting injector output and reducing injection times for superior performance.

The Spool Performance FX-350 is a game-changer in fuel system engineering, offering improved pressure and atomization for those looking to maximize their Audi RS Q8’s potential.

Why Upgrade?

The stock high-pressure fuel pump in your Audi RS Q8 can limit performance when tuning for higher power. The FX-350 delivers 90% more fuel flow, enabling you to safely increase horsepower, run larger turbos, and use higher ethanol blends. This upgrade is essential for performance enthusiasts looking to push their RS Q8 to the next level.

Enhanced Pressure

The FX-350 is engineered to deliver fuel at an impressive 35Mpa, a major improvement over the FX-200’s 25Mpa. Applying the physics principle Q=PxA (flow rate = pressure x nozzle area), the FX-350 increases fuel flow by 40%, ensuring your Audi RS Q8 gets the necessary fuel for optimal combustion, even in extreme performance conditions.

What’s Included in the Kit?

• 2 x FX-350 upgraded high-pressure fuel pumps
• 1 x Ethanol Content Monitor kit (optional), with mobile app
• 1 x Bosch spec 10-micron high-flow Fuel Filter
• Upgraded fuel lines and installation hardware
• Spool 10-micron filter unit

Spool 10-micron filter

Ensures top-tier filtration for your Audi RS Q8, protecting the high-pressure pump and injectors from debris without causing pressure drops in the low-pressure fuel system.

Spool Ethanol Content Monitor

The Spool ECA kit provides a digital readout of ethanol content and fuel temperature, accessible via a mobile app. Leveraging BLE 4.0 technology, it wirelessly connects to your smartphone while remaining compatible with other Bluetooth devices. The kit’s fuel lines are black nylon-coated, braided steel with a PTFE core, ensuring full E85 compatibility.

Are Tune Changes Required?

Yes, the FX-350 requires calibration adjustments to prevent damage. We provide calibration details for your tuner and can recommend experienced tuners familiar with this upgrade. Custom tuning is crucial to fully optimize the FX-350 for your vehicle’s specific setup and conditions.

Low-Pressure Fuel Pump Upgrade

To protect your high-pressure pump and injectors, ensuring proper low-pressure fueling is critical. Insufficient low-pressure fueling can damage the pump and void warranties. Make sure your fuel system upgrades include low-pressure pump improvements when necessary.

We recommend the torquebyte controller to increase your factory low pressure pump's output by 60% to make sure the hpfp is always receiving sufficient low side flow. Please visit

Torquebyte EA825 Low pressure Fuel System upgrade

Unlock the true potential of your Audi RS Q8 with the Spool Performance FX-350 upgrade.