Description
Fits: 2008-2012 Audi S5
Overview
The APR High Pressure Fuel Pump (HPFP) enhances fuel delivery capacity by 41% over stock, ensuring the direct injection system meets the demands of high horsepower applications. This upgrade increases pump displacement using high-quality components manufactured to strict tolerances.
How the Direct Injection System Works
- Low Pressure Fuel Pump (LPFP): Sends fuel from the tank to the HPFP at 4 to 6 bar.
- High Pressure Fuel Pump (HPFP): Elevates pressure to a maximum of 136 bar, supplying high-pressure fuel directly to the injectors.
The Problem
The pump's fuel displacement is linked to its internal bore size and camshaft stroke. Upgraded forced induction systems can overstrain the pump, particularly at lower RPMs, leading to inadequate fuel volume.
The APR Solution
APR significantly increases the HPFP's displacement, allowing for greater fuel volume across all RPMs. This ensures consistent fuel pressure even under demanding conditions.
Key Features
- 41% Increased Fuel Volume: Supports high-performance setups with increased demands.
- High-Quality Components: Utilizes genuine Hitachi parts for reliability and performance.
- Precision Engineering: Tolerances as tight as .00004" (dimensional) and .00005" (geometric).
- DLC Coated Piston: Provides enhanced surface hardness and durability.
- Comprehensive Rebuild: All internal seals are replaced, including spring seals, ensuring reliability.
Technical Specifications
- Material: Heat-treated bearing-grade stainless steel.
- Upgraded Spring: Weight matched to prevent float during operation.
- Factory Pivoting Head: Reduces cam follower wear and minimizes piston side loading.
Internal Testing
Each APR HPFP is assembled under stringent guidelines and tested on APR's test rig to verify proper function. This process identifies potential issues early, significantly reducing the risk of engine damage from pump failure.
Proven Track Record
APR has been a leader in HPFP upgrades since 2006, supplying components for numerous motorsport applications. With tens of thousands of pumps sold, APR has the expertise and manufacturing capabilities to deliver a reliable product.
OEM Components
APR HPFPs are constructed using only genuine Hitachi components, ensuring OEM-level reliability. All parts are made in the USA using advanced precision machinery.
Emissions Compliance
This product complies with the EPA’s Tampering Policy and is legal for on-street use in most states, excluding California. Testing for 50-state compliance is in progress.
Features Summary
- 41% Increase in Fuel Volume
- Supports High-Power Applications
- Fully Rebuilt and Tested Before Shipping
- DLC Coated Piston and Upgraded Spring
- Precision Machining with Tight Tolerances
