The AEM adjustable fuel pressure regulator is designed for EFI fuel systems and provides precise fuel pressure control under both vacuum and boost conditions. The regulator is ideal for motorsport, drag racing and other high-performance engine builds where a stable fuel supply is essential. It supports fuel systems for engines producing up to 1,000 horsepower.
The regulator features a 1:1 vacuum/boost reference, meaning fuel pressure increases in direct proportion to boost pressure. This maintains a constant pressure differential across the injectors, ensuring accurate fuel delivery for both naturally aspirated and turbocharged engines. Fuel pressure is adjustable from 20 PSI up to the maximum capacity of the fuel pump.
The housing is CNC-machined from 6061-T6 aluminum with a black anodized finish. The patented interchangeable outlet orifice allows the regulator flow to be matched to different fuel pumps, providing optimal performance across a wide range of EFI fuel systems.
Specifications:
Type: EFI return-style regulator (bypass)
Material: CNC-machined 6061-T6 aluminum
Finish: Black anodized
Adjustable fuel pressure: 20 PSI up to the fuel pump's maximum capacity
Pressure reference: 1:1 vacuum/boost reference
Power rating: Up to 1,000 hp
Fuel compatibility: Gasoline, E85 and alcohol-based fuels
Inlets: 2 x AN6 ORB (2 x 9/16"-18 UNF)
Return port: 1 x AN6 ORB (9/16"-18 UNF)
Return connection: 90° banjo with hose barb for original return hose
Mounting: Directly to a compatible fuel rail
Application: EFI fuel systems
Part number: 25-303BK
Fits:
Acura Integra GS-R 1.7 (1992-1993)
Acura Integra LS/RS/GS 1.8 (1990-1993)
Acura NSX 3.0 (1991-1996)
Acura NSX 3.2 (1997-2000)
Acura TL 3.2 (1996-1998)
Acura Vigor 2.5 (1992-1994)
Honda Civic VX 1.5 (1992-1995)
Honda Civic Si 1.6 (1989-1991)
Honda Prelude VTEC 2.2 (1993-1996)*
Honda Prelude Si 2.3 (1992-1996)*
Compatible engine codes:
B17A1 / B18A1 / C30A1 / C32B1 / C32A6 / D15B6 / D16A1 / D16A6 / G25A1 / G25A4 / H22A1* / H23A1*
*Requires AEM High Volume Fuel Rail (25-104BK) for proper installation.
