APR 2.0T EA888 Gen 3 High Pressure Fuel Pump Rebuild (HPFP) - MS100143
The APR High Pressure Fuel Pump (HPFP) dramatically increases the maximum volume of fuel the HPFP can deliver. In doing so, the direct injection fueling system is capable of satisfying fueling requirements set forth by high horsepower turbocharger systems, such as APR’s Stage 3+ EFR7163R ROW Turbocharger System for the MK7 Golf R, S3 and similar vehicles.
APR was an OEM supplier of HPFP components to VAG and has operated with a nearly perfect tract record since the program's motorsport backed inception in 2006. With thousands of pumps sold, APR has a wealth of knowledge and manufacturing techniques utilized in the production of critical fueling components with exceptional reliability.
In the early 2000’s, VAG began supplying engines with a new direct injection technology known as FSI. Unlike conventional engines of the past, fuel is sprayed directly into the cylinders under extreme pressure resulting in increased power with lower consumption rates and fewer emissions. The technology has spread across VAG’s entire lineup of modern gasoline engines and is present in the 2.0T EA888 Gen 3.
How the direct injection fueling system works
The engine’s fueling system can operate to a maximum of over 2,900 psi (200 bar) of pressure to correctly spray and atomize fuel directly into the engine’s cylinders. This is in contrast to multi-port injection vehicles of the past which typically operated around 40-60 PSI provided by a low pressure fuel pump. To generate these enormous pressures, the 2.0T EA888 Gen 3’s variable low pressure fuel pump supplies fuel to a cam driven and solenoid fired HPFP which in turn supplies the injectors with fuel.
A four point cam lobe located on the exhaust camshaft drives the 2.0T EA888 Gen 3’s Hitachi Generation III HPFP. As engine speed increases, so does the pump’s ability to displace a greater volume of fuel per minute. The maximum volume the pump can deliver per revolution on the four point cam lobe is dictated by the stroke length from the cam lobe’s lift and bore diameter of the pump’s internal pressurizing cylinder, which is increased when upgrading to an APR HPFP. It’s important to understand, despite the name, APR’s HPFP upgrade is not necessarily designed to increase the engine’s fuel rail pressure. The primary goal is to increase the volume of available fuel.
The APR solution
The engine’s fueling system is very capable without modification. However, on vehicles where rail pressure drops below the requested values, the APR HPFP is necessary to keep up with demand. The APR HPFP addresses fueling needs by dramatically increasing the displacement of the HPFP by increasing the bore diameter of the pump's internal pressurizing cylinder. In doing so the fueling system is capable of displacing a higher volume of fuel per minute at every RPM, satisfying fueling needs for various high horsepower applications. This upgrade is only required where suggested by APR.
The key to APR’s reliability comes in part by use of extremely high grade materials and manufacturing techniques. The most critical components within the HPFP are the enlarged plunger and barrel. Each matched set is created using medical grade precision machining techniques deeply quality controlled all within the USA with dimensional tolerances as tight as .00004” and geometric tolerances 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. Finally, to prevent float associated with altering the plunger’s mass, APR supplies each unit with a properly specified spring.
Ultimate reliability of this critical component is not easily created using inferior materials and manufacturing techniques. Across all direct injection markets, the community has come to see time after time, cheaper alternatives were met with sometimes irreversible engine damage.
All APR HPFPs are assembled in house under strict assembly guidelines to ensure ultimate reliability and accountability. After construction the APR fuel pump tester plays a critical role in the APR’s track record of success. The test stand allows each pump to undergo a critical initial break-in period after creation without risking first operation on a live engine. The stand simulates real world operating conditions while APR’s production teams inspect the pump for leaks. Solenoid operation is verified while ensuring the pump is operating within its design specifications. Each pump is then serialized and shipped in a highly protective box to ensure safety during shipping.
Each HPFP is sold as a rebuild or a newly rebuilt pump. If you want a rebuild, you send us your pump. We’ll inspect it, rebuild it, test it, and ship it back!