The APR Low Pressure Fuel Pump (LPFP) Upgrade is designed to ensure the low pressure fueling system is capable of delivering the proper volume of fuel from the fuel tank to the high pressure fueling system under high demand situations.
Challenges to upgrading the LPFP:
- Very little room for upgraded pump - OEM Pump requires a PWM signal - OEM pump controller overheats with high output pumps - Upgraded OEM pump controller not fully compatible - ECU modifications may be required - Secondary controllers often rely on physical boost signals
The factory LPFP sits in a basket submerged in the vehicle's gas tank. The pump operates off of a pulse-width modulated (PWM) signal sent from the pump's control module, which is mapped in the ECU. As fueling demand increases and decrease, the PWM signal adjusts to send only the required amount of fuel through the pump. Unfortunately upgrading the LPFP is not a simple drop in task. The pump's factory enclosure presents some packaging constraints limiting clean expansion to a larger unit. Likewise, doing so often results in overheating and subsequent protective shut down of the factory control unit as it's operating outside of its intended design. This is even true when installing larger and expensive factory units like those found on high output vehicles, such as the Audi TT RS and RS3. Furthermore, upgrading the LPFP control module with the matching expensive higher output control units present other issues as the controller receives CAN messages from integrated vehicle componentry not common on vehicles requiring an upgraded LPFP.
The APR Solution:
- Inline fuel pump - Fuel pump controller with proper ECU CAN bus communication - Clean mounting brackets included - Direct bolt on with no software required - APR took a multi-step approach to solving the low pressure fueling system and is pleased to present a clean and accurately controlled solution for high horsepower applications.
The APR LPFP System features a 255 LPH high-pressure inline fuel pump that sits between the HPFP and the factory LPFP. The included APR Auxiliary ECU sits on the factory CAN bus and receives critical operating information from the factory ECU to accurately control the pump. As fueling demands increase and decrease, the APR Auxiliary ECU controls output of the pump to deliver the desired volume of fuel to the HPFP. By connecting to the factory CAN bus, the APR Auxiliary ECU eliminate the need for less sophisticated and often problematic methods of controlling the upgraded pump. Because the pump only runs when needed, less power is consumed, fuel temperature is lower and noise, especially at idle, is essentially non-existent. Finally, with the fuel line disconnected, with the click of a button the APR Auxiliary ECU allows the user to quickly and easily empty the vehicle's fuel tank to make way for switching to higher octane fuels or for dry storage and transportation.