Performance High Pressure Fuel Pump Upgrade for Various Models by APR Tuning
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 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 200 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 camshaft dictated stroke), and engine speed. The pump is driven off of a lobe on the camshaft. Larger turbocharger systems, and ethanol usage are capable of taxing this system, especially in the mid to lower RPM range where fuel volume is lower.
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!
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.
Features
- Dramatically increases the volume of fuel displaced by the HPFP
- Maintains higher pressures under demanding situations
- Fully rebuilt in house
- Fully machine tested and broken in before shipping
- DLC coated piston
