SKU: 64745162772

Holley Terminator X MAX Engine Management Systems 550-918

Sale price$899.98 Regular price$999.98
Save 10%

Pay in installments of $250.00 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Sep 19 - Sep 24

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Holley Terminator X MAX Engine Management Systems 550-918TERMINATOR X MAX MPFI W TRANS CONTROL 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

TERMINATOR X MAX MPFI W/TRANS CONTROL

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 550-918 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:

  • Designed for GM LS 4.8/5.3/6.0 LS Truck Engines and LS2/LS3 with 58x Crank, 4x Cam and 4L60E/4L80E transmissions, and EV6 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" 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, and coming soon, 12.3" digital dash support!
  • Free EFI Tuning Software for complete control of your Terminator X power plant
  • Includes: 58x/4x LS Engine Main Harness - EV6 Injector Harness - 4L60E/4L80E Transmission Control Harness - Terminator X MAX ECU - ECU Main Power Harness - Bosch LSU 4.9 Wideband Oxygen Sensor - Input/Output Harness - and assorted vacuum adapters.

    Specs

    Brand Holley EFI
    Crank Reluctor 58x
    Emission Code 3
    Ignition Type GM LS 58x
    Injector Connector USCAR (EV6)
    Product Type Terminator X Max LS MPFI
    Terminator LS Options Fuel, Spark, Transmission
    Part Number 550-918
    Shipping Notes
    • Free Standard Shipping on $100+ Orders to the USA.
    • Except Preorder products are shipped in 48 hours.
    • Delivery to the USA:
    1. Standard Shipping : 3-10 business days
    • If time is of the essence, please consider selecting expedited delivery for faster service.
    Exchange/Return Notes
    • We offer a 30-day return/exchange service after receiving.
    • Final sale items are not eligible for returns or exchanges.
    • To process your return/exchange, please contact us at [email protected]
    • Please click here for more details>>> Return & Exchange Policy
    SKU: 64745162772

    Discover Niche Categories That Outsell

    Top-Converting Item to Boost Your Average Order

    4.8 ★★★★★
    Based on 16 reviews
    Sort
    Highest Rating
    Newest First
    Oldest First
    Product Reviews
    B
    Verified Purchase
    Bertha
    Lake Worth, US
    ★★★★★ 5
    Great jacket 🤩
    Size: Medium, Color: Bright Purple
    This jacket really impressed me🤩the material is feel good and the fit is perfect 😘the stylish is gorgeous 😘the color is a nice vibrant good quality true to size 🤩good fabric perfect for any occasions wedding party birthday church etc🤩absolutely worth the price 🫶
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on December 31, 2025
    M
    Verified Purchase
    Mellissa
    Waukegan, US
    ★★★★★ 5
    Perfect for Prom, the satin detail elevates the look
    Size: Medium, Color: Black, Size: Medium, Color: Black
    This sport jacket was a great item for prom. We had it altered and taken in a little to be more form fitting. It was lightweight enough to be comfortable and the color was a nice black with satin collar. It was a great value for the money and this is the second one I've bought. The first one was red for freshman homecoming. Fits true to size as this is a medium but we did want it a little more form-fitting.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on August 20, 2025
    Z
    Verified Purchase
    zeesmum
    Bozeman, US
    ★★★★★ 5
    well made
    Size: Medium, Color: Black
    My son looked SO handsome for Prom. This suit was surprisingly well-made for the cost. After pricing tux rental, this was a no-brainer.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on May 22, 2026
    G
    Verified Purchase
    Geoffrey Wilson
    Omaha, US
    ★★★★★ 4
    Jr
    Size: Large, Color: Royal Blue
    Nice jacket but sleeves run small. My son is 6'1.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on May 1, 2026
    M
    Verified Purchase
    Michael Buterbaugh
    San Leandro, US
    ★★★★★ 5
    Much better quality than I expected
    Size: X-Large, Color: Black
    Better than I expected, actually a quality jacket. I'd wear it every day. The fit is perfect and exactly my style. I can't say much about washabiity due to having mine drycleaned
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on December 10, 2025

    recommand products