SKU: 52678495650

Holley Terminator X MAX Engine Management Systems 550-916

Sale price$899.98 Regular price$999.98
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Description

Holley Terminator X MAX Engine Management Systems 550-916TERMINATOR X MAX MPFI W TRANS, LS1 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, LS1

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 550-916 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 LS1/LS6 engines with 24x crank reluctor with EV1 injectors and 4L60E/4L80E transmissions
  • 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 1-bar 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: 24x LS Engine Main Harness - EV1 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.

Application

  • 1998 - 2002 Chevrolet Camaro
  • 1997 - 2004 Chevrolet Corvette
  • 1998 - 2002 Pontiac Firebird

Specs

Brand Holley EFI
Crank Reluctor 24x
Emission Code 3
Ignition Type GM LS 24x
Injector Connector Jetronic / Minitimer (Bosch)
Product Type Terminator X Max LS MPFI
Terminator LS Options Fuel, Spark, Transmission
Part Number 550-916
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: 52678495650

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4.2 ★★★★★
Based on 26 reviews
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C
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Carol C
Dallas, US
★★★★★ 5
excellent pillows i bought two sets!!
Size: Firm Queen (2 Count), Color: Original White (Cooling)
I ordered these for my son who has neck issues and has gone through so many pillows trying to find one that he liked. They’re heavy, so i was worried that they might be “too” heavy to be able to sleep on comfortably, so I ordered a second set, one firmer than the other (just in case) and gave him a set for Xmas and he loved the first set so much without even trying the less firm ones.He also needs the cooling factor and these offered that, too. They are filled with pieces of memory foam (tons of it) and each pillow can be modified by removing some of the foam. The covers are beautiful, high quality fabric with a zipper so ts easy to remove or replace the foam pieces. The size is perfect and they keep their shape. I kept the second set i ordered rather than returning them and i love the pillows. I actually modified two by removing some of the foam pieces. I kept the foam pieces in a zippered pillow protector and i can always adjust mine when or if i need to. 1000% love these.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 22, 2026
A
Verified Purchase
Asha
Draper, US
★★★★★ 5
The Perfect Firm Pillow l
Size: Queen (1 Count), Color: Original White (Cooling)
It is everything it claims to be, cool, comfortable and strong. I got this for my husband first, he loves it and then got one for my son, he uses it to support his knees and has been sleeping much better since then. They both needed a firm pillow that is not super soft, firm but not achy. Finally found the perfect one.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 6, 2026
M
Verified Purchase
Mopardodgegirl
Omaha, US
★★★★★ 5
It works! Quality pillow.
Size: Standard (1 Count), Color: Original White (Cooling)
This does actually provide a cooling effect, and it's very comfortable! The accompanying literature is helpful too. I believe this to be a quality pillow for the price.
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Reviewed in the United States on June 2, 2026
J
Verified Purchase
jin
San Leandro, US
★★★★★ 5
Most comfortable pillow I’ve ever slept on
Size: Queen (1 Count), Color: Crescent White(cooling)
This is the most comfortable pillow I have ever slept on. It doesn't mash down like other pillows. Cradles my neck perfectly plus it’s cool. I broke my neck a couple of years ago and this pillow feels very good and comfortable. Definitely recommend to everyone. Ive used it since May and it’s retained its shape.
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Reviewed in the United States on June 6, 2026
A
Verified Purchase
AreTrue
Pawtucket, US
★★★★★ 4
Smell
Size: Queen (2 Count), Color: Original White (Cooling)
The fact that there are not more comments on the smell of these pillows has me worried about some of yall. Listen, I LOVE the weight, and the firmness, it’s perfect for that. However, these pillows are RANK. They have a very strong mildew-ish smell that lingers. I took the outer cover off and washed it and let the pillow air out for a few days, the smell is still very strong when you press your face against it, which one does because it is in fact designed for that purpose. It smells so bad. It’s nauseating. I can smell it through two pillowcases and blanket that I threw on top of them hoping an extra layer would trap the smell. I’ll bake them in the Texas sun tomorrow and hope that helps, because otherwise these are the perfect pillows for someone who wants to feel like they are hugging a torso but can’t stand the sound/feel of someone else breathing. I don’t know…4 stars, if the smell goes away I’ll come back. Update: many many days later. Either they don’t really smell anymore or I got use to it. They’ve held their firmness and shape well. I like them.
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Reviewed in the United States on March 9, 2026

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