WARNING: This product can expose you to chemicals that are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, visit www.P65warnings.ca.gov.The APR High Pressure Fuel Pump (HPFP) Upgrade (MS100077) is a critical performance component for the Audi S5 4.2L V8 (produced after November 2008). Designed to support high-horsepower applications—particularly supercharged builds—this upgrade increases the maximum volume of fuel the HPFP can deliver by a staggering 41% over stock. By increasing the internal bore diameter of the pump's cylinder, APR ensures that fuel pressure remains rock-solid even in the mid-to-low RPM range where factory pumps often struggle to keep up with increased demand.
Every APR HPFP is built using genuine Hitachi pump bodies and features internal components machined to aerospace-grade tolerances (as tight as .00004"). The plunger is crafted from heat-treated, bearing-grade stainless steel with a Diamond-Like Coating (DLC) for extreme surface hardness and reduced friction. To ensure out-of-the-box reliability, APR assembles these units in-house and validates every single pump on a specialized test rig to verify seal integrity and solenoid function before it ever reaches the customer.
Features:
- 41% Increase in Fuel Volume: Dramatically expands fueling capacity to support large power gains from superchargers or tuning.
- Ultra-Precise Engineering: Machined with .00004" dimensional and .00005" geometrical tolerances for unrivaled reliability.
- DLC Coated Piston: The diamond-like coating ensures exceptional surface hardness, reducing wear and friction on the internal plunger.
- Rigorous Testing: Each unit is fully machine-tested and broken-in on APR’s internal rig to prevent DOA failures or camshaft damage.
- Premium Materials: Uses certified bearing-grade stainless steel and weight-matched upgraded springs to prevent "pump float" at high RPM.
- OEM Integrity: Built using new factory pump bodies and genuine Hitachi components for perfect fitment and longevity.
- Reduced Cam Wear: Retains the factory pivoting head design to minimize cam follower wear and side-loading on the piston.
Product Contains:
- (2) Fully Rebuilt and Upgraded APR High Pressure Fuel Pumps (Matched Set for the V8)
- (2) Upgraded and Weight-Matched Springs
- (2) New Internal Seals and Hardware
Important Fitment Note: This specific part number is designed for Audi S5 4.2L FSI V8 models produced after November 2008. These are sold as a complete set to cover both banks of the engine. Specific ECU software is required to take full advantage of the increased fueling capacity.
Warranty: This product is supported by a Manufacturer's Warranty. Note: Manufacturer warranty terms are subject to change.
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