Holley Terminator X MAX Engine Management Systems

4.23 out of 5 stars 90 Customer Reviews

Holley Terminator X MAX engine management systems let you take control of your domestic V8 engine. They give you complete charge of your engine and self-learning fu

Holley Terminator X MAX engine management systems let you take control of your domestic V8 engine. They give you complete charge of your engine and self-learning fuel strategies, along with the proven, race-winning technology of Holley EFI—all at a budget-friendly price! Every MPFI Terminator X MAX features real-time fuel learn, high-impedance injector drivers, an integrated one-bar MAP sensor—and four programmable inputs and outputs, ideal for electric fans, boost control solenoids, progressive nitrous control, and much more. Also, Holley offers the X MAX systems with either or both drive-by-wire (DBW) throttle body control or transmission control. All kits come fully loaded with base maps for common domestic V8 engine combinations to get you out of the garage and onto the road or track fast. Order the model recommended for your vehicle application.

Features include:

* Holley EFI industry-leading, easy-to-use software suite allows full laptop access for advanced users
* Real-time fuel map learn—takes the guesswork out of tuning your base fuel table
* High-impedance injector drivers will safely power most standard injectors and Holley EFI injectors (will not control low-impedance injectors)
* Bosch LSU 4.9 wideband relays AFR information to the ECU for accurate reading and precise tuning control
* On-board one-bar MAP sensor is perfect for N/A or nitrous engine combos
* MAP sensor vacuum hose adapters
* 4 inputs: 12 V, ground, 5 V, and frequency
* 4 outputs: Ground, PWM, and for accessories
* Boost control: boost vs. time, boost vs. gear, boost vs. rpm, boost vs. speed, and boost safeties
* Nitrous control: single channel of wet or dry, progressive or non-progressive, rich/lean safeties, and target closed loop AFR; adjustable through touch screen
* Advanced tables can be used for any custom tables
* On-board diagnostic LEDs allow you to identify any critical engine issues at a glance
* 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
* Available with or without a 3.5 in. touch screen LCD hand-held with easy-to-use calibration wizard; allows you to quickly build a base tune for most V8 engines, as well as tuning and gauge display functions

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Holley Terminator X MAX Engine Management Systems 550-917

Engine Management Systems, Terminator X MAX, 8-Injectors, 8-Coil, Sensors, Trans and Tuner Controller, Chevy, LS, 4.8-6.0L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-917

4.63 out of 5 stars ( 16 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-919

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coil, Sensors, Trans and Tuner Controller, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-919

4.9 out of 5 stars ( 10 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-916

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coils, Sensors, Trans and Tuner Controller, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-916

4.64 out of 5 stars ( 11 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-934

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Analog, Trans and Tuner Controls, Chevy, LS, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-934

4.0 out of 5 stars ( 4 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-927

Engine Management Systems, Terminator X MAX, 8-Injectors, 8-Coil, Sensors, Trans and Tuner Controller, Chevy, LS, 4.8-6.0L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-927

3.88 out of 5 stars ( 8 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-917T

Engine Management Systems, Terminator X MAX, 8-Injectors, 8-Coil, Trans Control, Sensors, USB Tune Cable, Chevy, LS, 4.8-6.0L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-917T

1.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-926

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coil, Sensors, Trans and Tuner Controller, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-926

4.0 out of 5 stars ( 2 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-930

Engine Management Systems, Terminator X MAX, 8-Injectors, 8-Coils, Sensors, Chevy, LS, 4.8-6,0L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-930

3.0 out of 5 stars ( 3 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-919T

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Trans Control, Sensors, USB Cable, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-919T

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-932

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Analog Input, Tuner Controls, Chevy, LS, 5,7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-932

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-1317

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Plug-and-Play, Drive-by-Wire, Tuner/Trans Control, 4R70W, Ford, 4.6L, 5.4L, Kit

Part Number: HLY-550-1317

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-1318

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coils, Plug-and-Play, Drive-by-Wire, Tuner/Trans Control, 4R70W, Ford, 4.6L, 5.4L, Kit

Part Number: HLY-550-1318

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-929

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coils, Sensors, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-929

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-934T

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Trans Control, Analog, USB Tune Cable, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-934T

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-926T

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coil, Trans Control, Sensors, USB Tune Cable, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-926T

Not Yet Reviewed

Estimated Ship Date: Jan 12, 2026 if ordered today

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Estimated Ship Date: Jan 12, 2026 if ordered today

Holley Terminator X MAX Engine Management Systems 550-917-6

Engine Management Systems, Terminator X MAX, 8-Injectors, 8-Coil, Sensors, Trans and Tuner Controller, Chevy, LS, 4.8-6.0L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-917-6

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-916T

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coils, Trans Control, Sensors, USB Tune Cable, Chevy, LS, 5.7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-916T

5.0 out of 5 stars ( 2 )

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-1316

Engine Management Systems, Terminator X MAX, 8-EV1 Injectors, 8-Coils, Plug-and-Play, Drive-by-Wire, Tuner/Trans Control, 4R70W, Ford, 4.6L, 5.4L, Kit

Part Number: HLY-550-1316

Not Yet Reviewed

Estimated Ship Date: Tomorrow

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Holley Terminator X MAX Engine Management Systems 550-932T

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Analog Input, USB Cable, Chevy, LS, 5,7L, 1x Cam, 24x Crank, Kit

Part Number: HLY-550-932T

Not Yet Reviewed

Estimated Ship Date: Jan 12, 2026 if ordered today

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Estimated Ship Date: Jan 12, 2026 if ordered today

Holley Terminator X MAX Engine Management Systems 550-1319

Engine Management Systems, Terminator X MAX, 8-EV6 Injectors, 8-Coils, Plug-and-Play, Drive-by-Wire, Tuner/Trans Control, 4R70W, Ford, 4.6L, 5.4L, Kit

Part Number: HLY-550-1319

Not Yet Reviewed

Estimated Ship Date: Tomorrow