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". The plunger and barrel are created from certified and heat-treated bearing-grade stainless steel and the plunger undergoes a special diamond like coating process for exceptional surfaces hardness and ultra-reliable operation. To prevent float associated with altering the plunger's mass, APR supplies each unit with a properly specified spring. All necessary internal seals are replaced.Internal testing:All APR HPFPs are assembled in house under strict assembly guidelines. Each pump is then tested on our test rig to ensure the pumps operate as designed. This step is important for several reasons. It's critical in determining if a pump has a failure from incorrect install, a leaking seal, or a bad solenoid. Secondly, a seized pump on the vehicle at startup can cause damage to the engine's camshaft. By testing each pump, we all but eliminate these possibility.Proven track record:APR pioneered HPFP upgrades in the early days of VAG direct injection engines. Soon after, APR became an OEM supplier of HPFP and GDI components to VAG for use in various race cars, racing series, project cars, and concept vehicles.

• .00004" dimensional tolerances
• .00005" geometrical tolerances
• +37 AWHP / +50 AWFTLS (B9 2.9T E85 Stage 1 vs 1+ with HPFP)
• DLC coated piston
• Dramatically increases the volume of fuel displaced by the HPFP by 37%
• Fully machine tested and broken in before shipping
• Fully rebuilt in house
• Heat-treated bearing-grade stainless steel material
• Ideal for high output race cars and track use
• Includes a new OEM pump
• Maintains higher pressures under demanding situations
• Titanium retainer
• Upgraded and weight matched spring