JH Motorsports is pleased to now offer our High-Flow 255 LPH (Liter Per-Hour) In-tank Fuel Pump Upgrade Kit with our NEW High Flow Fuel Filter for the B6 A4-S4 and EARLY B7-S4!
For years there has been a lack of complete aftermarket fuel pump kits due to the factory fuel filter regulator assembly not being able to regulate the high volume of fuel that upgraded pumps provide. This is why we include our JHM Specific - High Volume Fuel Filter with our JHM Fuel Pump Upgrade Kits.
The issue with factory and replacement fuel filters is that the fuel regulator is not able to accept the high volume of fuel when at low speeds and at idle when the car isn't using as much fuel (as apposed to WOT) and the fuel pressures rise above the regulator specifications causing the fuel to not be able to return to the tank fast enough. This can cause fuel trim and other fuel related issues. Our High Flow Fuel Filter has a redesigned regulator to prevent these issues from occurring.
Here is a Fuel Pump Comparison Between the JHM 340LPH, JHM 255LPH, Bosch 044, Walbro 255, and OEM B6 and Early B7 S4. Note: The fuel systems on the B6 A4-S4 and Early B7-S4 run at 4bar.
NOTE: Due to the design of the OEM Fuel System, aftermarket pumps are not able to utilize the check valve at the bottom of the basket that would normally keep fuel in the basket when fuel level is low (roughly 30 DTE) and under hard acceleration when the fuel momentarily sloshes to the back of the fuel tank. This is only a minor inconvenience when you are low on fuel.