SKU: 5298063327

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 Jul 29 - Aug 3

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: 5298063327

    Discover Niche Categories That Outsell

    Top-Converting Item to Boost Your Average Order

    4.4 ★★★★★
    Based on 23 reviews
    Sort
    Highest Rating
    Newest First
    Oldest First
    Product Reviews
    N
    Verified Purchase
    Natalie R.
    Dallas, US
    ★★★★★ 5
    Looks great, doesn't hold much so measure carefully
    Color: Gray, Size: Rectangle
    I got this organizer for my husband to keep his stuff by the door. While it's a little smaller than I'd hoped, it looks great in the entryway. It's super easy to snap together, but feels like the material could be damaged easily if you're not careful. He is able to store his keys, wallet, and sunglasses in it, and throws hit hat on top. Overall we are really happy with it.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on January 31, 2026
    R
    Verified Purchase
    Rin
    Charlottesville, US
    ★★★★★ 5
    Perfect
    Color: Blue, Size: Square
    Just what I needed. The size is perfect as I didn’t want anything too large to place my watches and other accessories inside near the corner of my desk. Its size is essentially 7x7, and the design is sleek compared to other organizer holders. I got the color in blue and it looks stunning with the rest of my setup. I’m unsure about other reviewers, but mine came safely and the leather walls are decently thick, so it’s not too flimsy when buttoned together which holds very securely. There are hole spaces at the bottom corners once assembled, so if you have super small items such as beads or really small jewelry, they could potentially fall out, but most of my items are large enough that won’t be of concern. If you have a wire charger near by, the holes could be used to charge your smartphone inside, which has its own practical usage. Overall, I’d definitely recommend it if you’re on a lookout for a sleek but compact organizer holder, and I personally will consider getting another one in the future for myself for other household belongings.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on October 13, 2024
    A
    Verified Purchase
    Anonymous
    West Palm Beach, US
    ★★★★★ 5
    Useful and Handy !
    Very useful
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on January 11, 2026
    V
    Verified Purchase
    Valerie
    West Palm Beach, US
    ★★★★★ 1
    Tray
    Nice but way too small from what the picture showed
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on January 25, 2026
    M
    Verified Purchase
    Mojooooo
    Charlottesville, US
    ★★★★★ 5
    Perfect!! I’m obsessed!
    Size: Medium (6.8"W*4.4"D*2.2"H), Color: Beige
    So cute and great for travel! Lots of organization areas, easy to use, very durable and not made cheap, the zipper closes just fine and it’s compact for traveling or storing under the sink.
    WAS THIS REVIEW HELPFUL?YesReportShare
    Reviewed in the United States on May 1, 2026

    recommand products