Product Description
The AEM 25-100BK High Volume Fuel Rail is a black anodized billet-aluminum fuel rail designed for compatible Honda / Acura B-Series fuel systems, including AEM's officially listed B18B1, B18C1, and B18C5 applications.
With a 1/2-inch internal fuel bore, provisions for factory-style or custom fuel plumbing, and an auxiliary 1/8 NPT port, the 25-100BK can be used as anything from a straightforward replacement rail with factory-style plumbing to the foundation of a larger return-style JBtuned fuel system.
Quick Specs
- Manufacturer: AEM Performance Electronics
- AEM Part Number: 25-100BK
- Fuel Rail Bore: 1/2 inch
- Material: CNC-machined billet aluminum
- Finish: Black anodized with AEM laser engraving
- Auxiliary Port: 1/8 NPT
- Fuel-Line Compatibility: Factory-style or custom AN fuel plumbing
- Fuel Injectors Included: No
- Installation Hardware / Fittings: Included by AEM
AEM 25-100BK B-Series Fitment
AEM currently lists the 25-100BK for the following Honda B-Series engines:
- B18B1 – commonly found in 1994-2001 Integra LS / GS / RS applications
- B18C1 – 1994-2001 Integra GS-R
- B18C5 – U.S.-market Integra Type R applications
The 25-100BK is also commonly used in B20 and B20/VTEC combinations using a compatible B-Series intake-manifold and fuel-rail configuration. Because B20 builds can use different cylinder heads, intake manifolds, injectors, and fuel-system layouts, verify the particular combination before ordering.
1/2-Inch High-Volume Fuel Bore
AEM manufactures the 25-100BK with a 1/2-inch internal fuel bore. The larger rail volume helps support higher fuel-flow requirements and also helps dampen fuel-pressure pulsations generated by larger injectors.
AEM rates the rail itself for fuel-flow capability in applications up to 1,000 horsepower. This is a fuel-rail flow-capability specification and should not be interpreted as a horsepower rating for the complete vehicle or fuel system.
Actual fuel-system capability depends on the fuel pump, injectors, regulator, feed and return plumbing, filter, electrical supply, fuel type, engine combination, and tuning.
Factory Fuel Line or Custom AN Plumbing
The 25-100BK can be installed in more than one type of B-Series fuel-system configuration.
AEM supplies the hardware and fuel-line fitting needed to support the applicable factory-style fuel-line arrangement. The rail also provides threaded fuel connections for builders converting the engine to custom AN plumbing.
This flexibility is one reason the 25-100BK works well for both relatively simple B-Series builds and more complete aftermarket fuel systems.
Choose the Fuel Pressure Regulator That Matches Your System
The correct fuel-pressure-regulator setup depends on how the rest of the fuel system is being built.
Factory-Style / Rail-Mounted Regulator
The AEM rail retains the conventional Honda B-Series rail-mounted regulator layout, allowing compatible factory-style regulator configurations to be used.
AEM Adjustable Rail-Mounted Regulator
For these B18 applications, the corresponding adjustable AEM rail-mounted regulator is the AEM 25-300BK Honda / Acura Adjustable Fuel Pressure Regulator.
The 25-300BK mounts directly in the rail-mounted regulator position and provides an adjustable 1:1 rising-rate regulator solution while retaining the compact B-Series regulator layout.
External Regulator / Larger Custom Fuel System
For larger return-style fuel systems, the rail can instead be incorporated into a custom configuration using an external regulator such as the AEM 25-302BK Universal Adjustable Fuel Pressure Regulator.
External-regulator systems require the rail, regulator, feed, and return plumbing to be configured together. JBtuned fuel systems are available with different rail and regulator connection arrangements so the system can be built around the components installed on the vehicle.
1/8 NPT Auxiliary Port
The rail includes an additional 1/8 NPT port that AEM provides for applications such as a fuel-pressure gauge or an additional fuel supply for a wet nitrous system.
The port can also provide a convenient location for compatible fuel-pressure instrumentation when the rest of the fuel system is configured appropriately.
Starting with the OEM Honda Fuel Filter?
If you are keeping the factory firewall-mounted Honda fuel filter and only need the engine-side feed connection, the JBtuned B-Series OEM Filter-to-Rail Fuel Line can be configured for compatible aftermarket B-Series fuel rails such as the AEM 25-100BK.
This is the simpler JBtuned Level 1 approach: retain the OEM filter and existing chassis plumbing while upgrading the filter-to-rail feed line.
Building a Tucked or Higher-Capacity B-Series Fuel System?
If the fuel rail is being installed as part of a turbocharged, higher-output, E85-capable, or cleaner tucked B-Series build, the fuel rail should be considered as one component of the complete fuel-delivery system rather than as an isolated upgrade.
The JBtuned B-Series Fuel Line Tuck Kit removes the large OEM firewall filter and upgrades the engine-bay feed and return plumbing while retaining the factory chassis fuel lines.
For builds that need the factory chassis plumbing replaced from the tank to the engine and back, use the JBtuned B-Series Full Tucked Fuel System.
For a complete PTFE system specifically configured around ethanol-content-sensor integration, see the JBtuned B-Series Complete Flex-Fuel System.
What Is Included?
AEM supplies the 25-100BK rail with the installation hardware, fittings, and injector O-rings required for the supported AEM rail installation.
- AEM 25-100BK high-volume fuel rail
- Applicable installation hardware
- Factory fuel-line fitting
- Injector O-rings
- 1/8 NPT auxiliary-port plug
Fuel injectors, fuel-pressure regulator, aftermarket AN fuel lines, fuel pump, and other fuel-system components are not included unless purchased separately.
Installation Notes
Fuel pressure must be safely relieved before removing or servicing the fuel rail. Inspect injector seals, O-rings, washers, and other sealing components during installation and replace damaged components as required.
After installation, pressurize the fuel system and carefully inspect the rail, injectors, regulator, fittings, and fuel-line connections for leaks before starting or operating the vehicle.
If you are building a B20, engine swap, or custom fuel-system combination and are unsure which fuel rail, regulator, or JBtuned fuel-system configuration is appropriate, contact JBtuned before ordering.
