Skip to main content
ASK OUR EXPERTS
1-866-464-6553

Holley EFI Terminator X Max - Gen III 4.8/5.3/6.0 GM Truck Engines

24x Crank - 1x Cam - Multec 2 Injectors - 4L60/80 Transmission Control - 3.5-inch Touchscreen

Injector Connector

Crank Reluctor

Drive-By-Wire

Handheld Included

Transmission

Part # 550-917
17 Reviews

Holley EFI Terminator X Max - Gen III 4.8/5.3/6.0 GM Truck Engines

In Stock
Free Shipping - Lower 48 US States
$1,828.95
Add to Wishlist
Starting at $161 a month with Learn More
3

Emissions

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles.

See Emissions Details
Take control of your LS engine with Terminator X Max! Don't settle for a junkyard ECU with a cumbersome tuning interface when you can have complete control of your engine, self-learning fuel strategies and the proven, race-winning technology of Holley EFI at a budget-friendly price! Terminator X Max features real-time fuel learn, high impedance injector drivers, an integrated 1bar MAP sensor, and 4 programmable inputs and outputs. The inputs and outputs are ideal for electric fans, boost control solenoids, progressive nitrous control, and much more. Part number 550-917 also has 4L60E or 4L80E Transmission control. Terminator X Max comes fully loaded with base maps for common LS engine combinations to get you out of the garage and on the road/track fast. The 3.5" touch screen LCD handheld contains an easy to use calibration wizard as well as tuning and gauge display functions. Also included is Holley EFI's industry-leading, easy to use software suite that allows full laptop access for advanced users. Whether you are building a budget beater or a boosted race car, Terminator X MAX has the features and technology you need at a price that won't break the bank!

Features:

  • For GM LS 4.8/5.3/6.0 Truck Engines with 24x crank reluctor, Transmission Control, and Multec 2 Injectors
  • Real-Time fuel map learn, takes the guess work out of tuning your base fuel table
  • High Impedance Injector Drivers will safely power most Stock LS injectors, and Holley EFI Injectors. Injector support chart provided in the instructions (Will not control Low Impedance Injectors)
  • All of the new Terminator X Max systems utilize the Bosch LSU 4.9 wideband to relay AFR information to the ECU for accurate reading and precise tuning control.
  • On-Board 1bar MAP sensor, is perfect for N/A or Nitrous engine combos. If your combination requires a 2+Bar, we recommend GM 12592525, and our adapter part number 558-416.
  • MAP Sensor vacuum hose adapters (1/8th – ¼ and 3/16ths)
  • 4 Inputs – 12v, Ground, 5v, and Frequency, for things such as additional pressure sensors, or activation triggers for nitrous activation, or a trans brake
  • 4 Outputs – Ground, PWM - , for accessories such as; fans, boost control, nitrous control, IAC Kit, and More
  • Boost Control – Boost vs Time, Boost vs Gear, Boost vs RPM, Boost vs Speed, Boost Safeties
  • Nitrous Control – Single Channel of Wet or Dry, Progressive or Non-Progressive, Rich/Lean Safeties, and target Closed Loop AFR
  • Advanced Tables – 4x 1D Tables, 1x 1D per Gear Table, 4x 2D Tables, 1x 2D per Gear Table, can be used for any custom tables you can dream up, such as Flex Fuel Sensor Offset Table, or a custom fuel or oil pressure safety!
  • On-Board Diagnostic LEDS for: ECU Power – Engine Run – Wideband Status – TPS Calibration – Crank Signal –Cam Signal. Allow you to identify any Critical engine issues at a glance
  • The included 3.5-inch Touchscreen Handheld contains a calibration wizard, that allows you to quickly build a base tune for any LS engine. Additionally, the handheld provides internal data-logging and a fully customizable gauge display.
  • The compact ECU size allows you to mount it virtually anywhere. Remember, diagnostic LEDS must face up!
  • Plug and play compatible with more Holley EFI accessories such as; analog style gauges, shift lights, various modules, as well as 5, 6.86 and 12.3-inch Digital Dashes
  • Free EFI Tuning Software for complete control of your Terminator X power plant

About Holley EFI

Find standalone EFI for LS, Coyote, Hemi and more at Holley.com. From engine swapping to managing up to 4000 horsepower, we have a solution for every project!

Brand Holley EFI
Crank Reluctor24x
Drive-By-WireNo
Emission Code3
EngineGen III GM Truck
Handheld IncludedYes
Ignition TypeGM LS 24x
Injector ConnectorMultec 2
Product TypeEFI System
Terminator LS OptionsFuel, Spark, Transmission
Transmission4L60E/4L80E
UPC090127060834
Part Number550-917
3

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles.


The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

  • 1965 and older U.S. manufactured California Certified vehicles
  • 1967 and older U.S. manufactured Federally Certified vehicles
  • 1967 and older Foreign manufactured vehicle


WARNING: It is against the law to install this part on an Emissions Controlled Vehicle


The following vehicles are considered Emissions Controlled Vehicles:

  • 1966 and newer U.S. manufactured California Certified vehicles
  • 1968 and newer U.S. manufactured Federally Certified vehicles
  • 1968 and newer Foreign manufactured vehicle
Not recommended for 4x4 applications with electronic transfer cases. Not compatible with 4L6X transmissions from model year 1995 or before due to year-by-year changes in converter lockup and downshift strategy.
Reviews
17

4.9 out of 5 stars

  • 5 star

    94%

  • 4 star

    6%

  • 3 star

    0%

  • 2 star

    0%

  • 1 star

    0%

Your Review

Items 1 - 17 of 17
  per page
Page:
  1. 1
Items 1 - 17 of 17
  per page
Page:
  1. 1

*Free Shipping & Handling only offered to the contiguous US on orders over $149, excludes clearance parts and oversized packages.

Some parts are not legal for use in California or other states with similar regulations.