APR FSI High Pressure Fuel Pump

While modifying the 2.0T FSI engine beyond factory power levels, it became quickly apparent to APR that an additional volume of high-pressure fuel was needed to make horsepower, especially in the midrange (3000-5000rpm) of the powerband. To understand why this fuel is needed for the midrange, one must first understand how the fuel delivery system works in the 2.0T. A low pressure fuel pump (which varies from ~40-95psi) delivers fuel from the gas tank to the engine. Then, in order to spray fuel directly into the combustion chamber, a high-pressure, camshaft-driven pump pressurizes the fuel to upwards of 130bar (almost 1900psi !). Unfortunately, on cars that have many modifications the stock fuel pump cannot flow enough volume of fuel to maintain the system pressure, and the car gets the familiar “fuel cut” that so many modified customers experience. The limitation of how much volume of fuel the high pressure pump can flow is dependant upon the volume displaced by the pressurizing cylind