APR Direct Injection High Pressure Fuel Pump

APR High Pressure Fuel Pump Upgrades: Motorsport-Proven Fueling for VAG Platforms

When a performance build demands more power — whether through a larger turbocharger, an aggressive ECU tune, or high-ethanol fuel like E85 — the factory high pressure fuel pump (HPFP) quickly becomes the limiting factor. APR has been solving this problem since 2006, and their lineup of direct injection high pressure fuel pumps remains the benchmark for VAG enthusiasts across the globe.

Why the Stock HPFP Runs Out of Fuel

In a gasoline direct injection (GDI) system, a low-pressure pump in the fuel tank delivers fuel at roughly 4–6 bar to the high pressure fuel pump, which then raises pressure up to a maximum of 200 bar before delivering it to the injectors. The volume of fuel the HPFP can displace is directly tied to the internal bore size of the pump and the camshaft-dictated stroke — not tuning software alone. Larger turbocharger systems and ethanol usage are capable of taxing this system, especially in the mid to lower RPM range where fuel volume is inherently lower, leading to dangerous fuel cuts.

APR's Solution: More Displacement, More Volume

APR's approach is elegantly direct: they increase the bore diameter of the pump's internal pressurizing cylinder to raise overall pump displacement. Depending on the application, this increases the maximum volume of fuel the HPFP can deliver by up to 41% over the stock unit. On the B9 2.9T platform running E85 fuel, APR's HPFP upgrade translated to an additional 37 AWHP and 50 AWFT-lbs over a Stage 1 ECU tune alone — a substantial real-world gain that illustrates just how critical fueling headroom is for high-output builds.

Precision Engineering & OEM-Grade Components

What separates APR's HPFPs from lesser alternatives is the level of precision involved. Dimensional tolerances on APR HPFP internals are as tight as .00004", and geometric tolerances reach as tight as .00005". The plunger and barrel are machined from certified, heat-treated bearing-grade stainless steel, and the plunger itself receives a special diamond-like coating for exceptional surface hardness and long-term reliability. All upgraded components are manufactured in the USA using medical-grade precision machinery.

APR also insists on using only genuine Hitachi pump bodies, sensors, and critical housing components — made in Germany — to ensure OEM-level reliability. Every pump is assembled in-house under strict guidelines and individually bench-tested on APR's test rig before shipping, helping to catch any installation issues, leaking seals, or solenoid faults that could otherwise damage an engine's camshaft at first startup.

Coverage Across the VAG Lineup

APR offers HPFP upgrades for a wide range of VAG platforms, including the 2.0T EA113, 2.0T EA888 Gen 3, 2.5T, 2.9T and 3.0T EA839, and the 4.2L FSI V8 — covering everything from the VW GTI and Golf R to the Audi S4, S5, RS5, and even Porsche Cayenne and Panamera applications. Both new pump and rebuild kit options are available, giving owners flexibility based on their current pump's condition.

APR pioneered HPFP upgrades in the early days of VAG direct injection engines and subsequently became an OEM supplier of HPFP and GDI components to the VAG Group for use in race cars and factory concept vehicles. With tens of thousands of pumps sold and a motorsport-backed track record stretching back to 2006, APR's HPFPs represent some of the most validated fuel system hardware available for the platform.