USP Stage 3 Auxiliary Low Pressure Fuel System for Audi and Volkswagen
As many of you know, the fuel system for the 2.0T FSI platform is composed of two separate systems: the high pressure system (50-130bar), and the low pressure system (3-5bar). While, the limitations of high pressure fuel delivery have been eliminated by products such as the APR upgraded rail pump, the low pressure system has been ignored.
Through USP's research and development at USP Motorsports, they were able to determine that the low pressure fuel system is nearly maxed out when producing around 350whp, running an a/f ratio between 11.0:1 – 11.5:1. This limitation is a result of the in-tank fuel pump being maxed out. By replacing the factory in-tank fuel pump with an APR in-tank fuel pump, the low pressure fuel system sits on its limits at around 400whp, while still maintaining the same a/f ratio mentioned above.
Developing a low pressure fuel system to work properly with the complicated components and electronics of the 2.0T FSI was no easy task. The in-tank fuel pump that runs the FSI does not function like a traditional fuel pump. Meaning, the fuel pump does not always receive a full 12volt signal while the car is running like a traditional fuel pump does. Instead, the ECM controls the fuel pump through a Pulse-Width Modulated signal (PWM). This quickly ruled out the ability to add an inline fuel pump. Other options were explored but, adding a secondary in-tank fuel pump was the end result.
Features
- High flow in-tank fuel pump
- Load-based fuel pump controller
- Preassembled fuel lines and fittings
- Fuel distribution block w/check valve
- All wires, terminals, and connectors
- Detailed instructions included
This system is estimated to be good for around 700 wheel horsepower and is the same system used on our in-house MK5 GTI which produces 605whp
