Holley Performance Products started working on some of the very first cars with Henry Ford back in the early 1900s. They have been in the industry for over 100 years but began by manufacturing carburetors, which powered every NASCAR Sprint Cup team and NHRA Pro Stock champion for almost four decades. When both organizations switched to EFI, Holley pioneered that technology as well. Holley not only designs, engineers, and assembles its own parts, but Holley also put them through rigorous tests like bench testing, lab testing, and track testing. Now Holley’s products for GM’s infamous LS engine are dominating the market and for a good reason.


Factory ECUs tend to have pre-programmed tuning chips or an unfriendly tuning interface. This means more likely than not, you’ll end up tangled in a 20-year-old engine harness and struggling to reprogram an outdated, stock ECU. The Terminator X line made by Holley is known for offering a plug and play engine management system for domestic V8s so you can retrofit your vehicle with everything from modern fuel injection to drive by wire and transmission control for the 4R70W as well as GM-based transmissions.

Other useful features include onboard diagnostic LEDs to easily identify critical engine issues at a glance, an integrated 1bar MAP sensor, 4 input/output channels that can be programmed for accessories or sensors, boost control, nitrous control, and free EFI tuning software for complete control over the ECU.


Fox-body Mustang kits are among the newly added product line, and vehicle-specific modifications have been made for easy installation. These kits also include vehicle-specific installation guides to help you quickly and accurately turn your 5.0L Fox-body into an EFI Terminator X powered beast!

Official Release:

Holley’s popular Terminator X lineup has now expanded to accommodate Ford based applications using 289-302W, 351W, and 460 engines. Introducing Fox-body Mustang-specific kits which utilize a custom mounting bracket to place the ECU inside of the cabin directly below the passenger seat and a new, more extended main harness designed to aid in routing. Other features include integrated Ford idle air control motor and throttle position sensor connections as well as plug and play functionality with TFI ignition systems. The Terminator X Max system now supports Ford 4R70W transmissions as well as newer 4L60E / 4L80E GM transmissions for customers with mixed combinations.