C43 Spool FX-350 upgraded high pressure pump kit (M276)

What is the FX-350?

Introducing the Spool Performance FX-350: the next evolution in high-pressure fuel pumps, surpassing our previous model, the FX-200, in both performance and efficiency.

Enhanced Pressure and Flow: The FX-350 is engineered to deliver fuel at an impressive 35Mpa, significantly higher than the 25Mpa offered by the FX-200. This increase in pressure, following the physics equation Q=PxA (where Q is flow rate, P is the change in pressure, and A is the area of the injector nozzles), results in a higher flow rate through the injectors, ensuring more fuel is available for combustion, crucial for high-performance applications. The FX-350 makes your injectors flow 40% more fuel before maxing out the injection window limitations. 

Improved Fuel Atomization: The higher pressure of the FX-350 aids in better atomization of fuel. In direct-injected engines, finer fuel droplets lead to more efficient combustion. This improvement in atomization means the fuel mixes more thoroughly with air, resulting in a more complete burn. This efficiency not only increases power output but also enhances fuel economy and reduces emissions.

The Spool Performance FX-350 stands as a testament to advanced automotive engineering, offering unmatched efficiency and performance. Its ability to deliver fuel at higher pressures, coupled with superior atomization, makes it an essential upgrade for those looking to maximize the potential of their high-performance engine.

Why do you need it?

The stock HPFP on the M276 Motors is severely limited in capacity when trying to tune and raise the output of the motor. The FX-350 adds 90% more flow to the equation, raising the fueling limits on the platform and helping you run bigger turbos and/or higher ethanol concentration blends.

Spool 10-micron filter unit

Our 10-micron filter unit boasts the best filtration available Mercedes market without any noticeable pressure drop in the low side fuel system. The filter unit helps keep the high-pressure pump and injectors safe by protecting them against debris and is highly recommended.

Spool Ethanol Content Monitor

The spool ECA kit  features a digital readout of in-tank ethanol content and fuel temperature. It includes our SPOOL Ethanol content analyzer app on mobile and readouts are delivered via BLE 4.0 low energy technology. BLE4.0 allows you to use your regular Bluetooth devices on your mobile devices while being connected to the SPOOL ECA module. Fuel lines used in the kit are black nylon coated, braided steel PTFE core and are 100% E85 compatible.

Are tune changes required?

The upgraded pumps do require calibration changes. It is important to apply these changes prior to starting the car with pumps installed to avoid any possible damage and void of warranty. 

Spool Performance can provide calibration details to your existing tuner and/or help you connect with established tuners who are experienced with these pumps. Custom tuning is required to get maximum output out of the upgraded pump setup for your specific vehicle setup and ambient conditions. Spool Performance is a hardware manufacturer and does not provide custom tunes, but can assist with questions your tuner may have.