AuxJection | LT1 & LT4 Magnuson 2650

Need more fueling than the LT4 DI system can support, but don’t want to rely on meth injection or invest in a full port-injection setup?

AuxJection  fills the gap with a clean, factory-style solution that installs easily and integrates seamlessly with the ECU.
 

HOW IT WORKS

AuxJection is a fully integrated auxiliary fuel-injection solution engineered to work within your vehicle's factory ECU—no external controllers, or piggybacks required. By utilizing custom ECU software (detailed instructions provided in your kit) that gets written to the ECU, AuxJection drives additional port-style injectors with the same precision you would expect from the stock controller.

AuxJection's internal calibration logic uses real-time ECU data to calculate and deliver auxiliary injector pulse width on the fly when a user-specified duration of direct injection window is met. After installation, the vehicle tunes no differently than if it were equipped with a higher-capacity fuel system from the factory.

The included fuel line set reroutes the low-pressure feed from the DI system at the firewall, through the throttle-body assembly, and returns it to the DI system inlet—allowing the auxiliary system to share the OEM low-pressure circuit without modifying factory hard lines. The plug-and-play harness combined with the pre-made fuel lines make this kit the EASIEST installing product on the market for adding an auxiliary fuel source. 

COMPATIBILITY:

• Only compatible with LT1/LT4 Magnuson 2650 applications
• Compatible with stock throttle body up to 103mm bore
• Adds approximately 1 inch to the supercharger snout
• Depending on your intake, minor tube or coupler modifications may be required
• This product does not fit Camaro SS or ZL1 with a standard Roto-Fab intake
• Roto-Fab Big Gulp and JLT large tube intakes are compatible with minor modifications; fitment of other large tube intakes is not guaranteed
• May have belt-to-throttle body clearance issues with aftermarket idler relocation brackets; fitment is only guaranteed with the stock belt drive setup
• A custom throttle body to intake tube coupler is currently in development to simplify Camaro intake tube installation (expected availability: May 2026)
• DO NOT use with VP Import, Q16, or other MTBE oxygenated fuels

FLEX-FUEL ADD-ON OPTIONS:

OPTION 1:  Use Existing Flex-Fuel Sensor [Include Integrated Harness] – This plug-and-play harness includes integrated flex-fuel sensor wiring and required fittings for a clean AuxJection + flex-fuel solution with all ECU connections in one harness.

Note: Flex-fuel sensor must be mounted in the same location as shown in the product photo. If you already have a flex-fuel kit installed, proper fuel line fitment cannot be guaranteed, as the lines are designed for a specific routing configuration. Existing hardware may need to be removed, but your sensor can be reused.

OPTION 2: Include Flex-Fuel Sensor & Integrated Flex-Fuel Harness – Includes harness, fuel line fittings, and flex-fuel sensor for a complete, seamless installation. Everything needed for adding AuxJection and flex-fuel capability at the same time.

IMPORTANT:

Custom ECU software is required. You must send us your current tune file to modify. (See custom software | tune file process dropdown below)
AuxJection will not function until the modified file is written to the ECU. *ECU flashing tools are not included.

Please be sure to read through the dropdowns below before ordering AuxJection