The APR High Pressure Fuel Pump (HPFP) increases maximum volume of fuel the HPFP can deliver by 41% over stock! In doing so, the direct injection fueling system is capable of satisfying fueling requirements set forth by high horsepower setups. This is accomplished by increasing the displacement of the pump using high quality components to exacting tolerances.How the direct injection system works:A low pressure fuel pump (LPFP) in the fuel tank delivers fuel to the high pressure fuel pump (HPFP) at roughly 4 to 6 bar. Fuel pressure is then bumped up to a maximum of 110-130 bar, depending on factory parts, with the HPFP. Finally, high pressure fuel is delivered to the injectors, which spray directly into the cylinders.The problem:The volume of fuel the HPFP pump can displace is directly tied to the displacement of the pump (Internal bore size, and cam shaft dictated stroke), and engine speed. The pump is driven off of a three lobe cam shaft, and as such, the pump cycles at 1.5 times the engine speed. Even the factory K03 and K04 turbochargers are capable of taxing this system, especially in the mid to lower RPM range where fuel volume is lower.The APR solution:We dramatically increase the volume of fuel the HPFP can displace at every RPM by increasing the displacement of the HPFP. This is accomplished by increasing the bore diameter of the pump's internal pressurizing cylinder. It's important to understand, despite the name, a HPFP upgrade is not necessary designed to increase the engine's fuel rail pressure. The primary goal is to increase the volume of fuel available, which will keep fuel pressure steady even in the most demanding of situations!High quality components and extreme tolerances:The HPFP internals must be machined to extreme tolerances and installed in a clean environment or the pump can easily fail. Dimensional tolerances on the APR HPFP are as tight as .00004" and geometric tolerances are as tight as .00005".

Genuine APR. Part number MS100016.

Ships from US warehouse.

WARNING: California Proposition 65 — this product can expose you to chemicals known to the State of California to cause cancer or reproductive harm.

Note: Not CARB approved — not for sale or use on pollution-controlled vehicles in California.