APR offers high-pressure fuel pump rebuild kits for a variety of applications, including Audi and Volkswagen models. The high-pressure fuel pump (HPFP) increases maximum volume of fuel the HPFP can deliver by 41 percent 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 3-lobe camshaft, 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:
APR dramatically increases 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, an HPFP upgrade is not necessarily 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 in. and geometric tolerances are as tight as .00005 in. 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 surface 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 internal seals are replaced, including the spring seal, and the tip of the pump retains the factory pivoting head to reduce cam follower wear and piston side loading.

This kit is a rebuild of your factory pump. A working pump must be sent to APR.

Pump rebuilds are applicable to the 1.4T EA111, 2.0T EA113, 3.2L FSI V6, 3.6L FSI V6, 4.2L FSI V8, 5.2L FSI V10 (S6/S8), MazdaSpeed 3 (07-13), and MazdaSpeed 6 (06-07).

Additional product details:

* Dramatically increases the volume of fuel displaced by the HPFP by 41 percent
* Maintains higher pressures under demanding situations
* Fully rebuilt in house
* Fully machine tested and broken in before shipping
* Rebuilds your factory pump
* Upgraded and weight-matched spring
* DLC coated piston
* Heat-treated bearing-grade stainless steel material
* Supports big power
* Spring seals replaced