Holley EFI Kit Terminator X For LS1/ LS6 Engine With 24X Crank 4X Cam/ EV1 Injectors
Highlights
- Boost and Nitrous Control
- 3-1/2" Touchscreen
- Precise Tuning
- Real-Time Fuel Map
Holley Terminator X EFI Kit for an LS1 or LS6 Engine with a 24X Crank Reluctor and 4X Cam with EVI Injectors.
Take control of your ECU and 4L60E/4L80E transmission with the precise tuning capabilities of a Holley Terminator X EFI Kit 550-916! The EFI conversion is built for LS1 or LS6 engines with a 24X crank reluctor and 4X Cam with EVI injectors, which is controlled by a 3-1/2" handheld touchscreen for quick base tuning. Take the guesswork out of the picture by taking advantage of the self-learning fuel table strategies thanks to real-time fuel maps and charted injector support instructions! The Terminator X series also features high-impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and outputs.
Features and Benefits:
- Learn with Real-Time Fuel Mapping and Strategies
- High Impedance Injector Drivers Safely Power Most Stock or Holley LS/EFI Injectors
- Bosch LSU 4.9 Wideband Relays AFR Information to ECU
- On-Board 1-Bar MAP Sensor for Nitrous Engine Combos
- MAP Sensor Vacuum Hose Adapters
- Boost Control over Time, Gear, RPM, Speed, and Safeties
- Nitrous Control over Single Wet/Dry Channels, Progressive or Non-Progressive, Rich/Lean Safeties, and target Closed Loop AFR
- On-Board Diagnostic LEDs for ECU Power, Engine Run, Wideband Status, TPS Calibration, Crank Signal, and Cam Signal
- 3-1/2" Handheld Touchscreen Calibration Wizard for Base Tuning
- Internal Data-Logging and a Fully Customizable Gauge Display
- Free EFI Tuning Software for Complete Terminator X Power Plant Control
Customize your fuel map tables with advanced configurations, such as 4x 1D tables, 1x 1D per gear table, or 4x 2D tables, 1x 2D per gear table. Satisfy your curiosity with data collected from fuel sensor offset, oil pressure safety, and more. A simple, at-a-glance handheld touchscreen allows you to identify any critical engine issues with diagnostic LEDs, so you can keep improving. Terminator X conversion allows you to keep experimenting with 4 inputs – 12v, Ground, 5v, and Frequency – with your choice of pressure sensors, or activation triggers for nitrous activation or trans braking. Additionally, 4 outputs for Ground and PWM are also included for accessories such as fans, boost control, nitrous control, IAC Kit, etc.
Included:
- 24x LS Engine Main Harness
- EV1 Injector Harness
- 4L60E/4L80E Transmission Control Harness
- ECU Main Power Harness
- Input/Output Harness
- Terminator X MAX ECU
- Bosch LSU 4.9 Wideband Oxygen Sensor
- Assorted Vacuum Adapters (1/8th – 1/4th and 3/16ths)
Additional Notes:
- The injector support chart provided in the instructions will NOT control Low Impedance Injectors.
- The compact ECU size allows you to mount it virtually anywhere, as long as diagnostic LEDs face upwards.
- Plug-and-play is compatible with more Holley EFI accessories such as analog-style gauges, shift lights, various modules, and a 12.3" digital dash support.
Fitment:
- GM LS1/LS6 Engines with 24x Crank Reluctor with EV1 Injectors and 4L60E/4L80E Transmission
Tech Tip: If your combination requires a 2+Bar, GM 12592525 with adapter, P/N: 558-416 is recommended.
California Residents: Proposition 65 Warning

Vehicle Fitment
This product will fit the following Bronco years:
This product will fit the following C/K years:
- 1988,
- 1989,
- 1990,
- 1991,
- 1992,
- 1993,
- 1994,
- 1995,
- 1996,
- 1997,
- 1998,
This product will fit the following C10 years:
- 1960,
- 1961,
- 1962,
- 1963,
- 1964,
- 1965,
- 1966,
- 1967,
- 1968,
- 1969,
- 1970,
- 1971,
- 1972,
- 1973,
- 1974,
- 1975,
- 1976,
- 1977,
- 1978,
- 1979,
- 1980,
- 1981,
- 1982,
- 1983,
- 1984,
- 1985,
- 1986,
- 1987,
This product will fit the following F-100 years:
- 1948,
- 1949,
- 1950,
- 1951,
- 1952,
- 1953,
- 1954,
- 1955,
- 1956,
- 1957,
- 1958,
- 1959,
- 1960,
- 1961,
- 1962,
- 1963,
- 1964,
- 1965,
- 1966,
- 1967,
- 1968,
- 1969,
- 1970,
- 1971,
- 1972,
- 1973,
- 1974,
- 1975,
- 1976,
- 1977,
- 1978,
- 1979,
This product will fit the following Mustang years: