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Ships within 48 hours · Estimated delivery Jul 8 - Jul 13
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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:
- 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
4.8 ★★★★★
Based on 927 reviews
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Product Reviews
★★★★★ 5
Good value
Model: NewSLS50_52, Model: NewSLS50_52
Working perfectly. Install of stereo equipment and carpet left me wanting some heat and sound resistant materials.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 23, 2026
★★★★★ 5
BUY THIS ONE!
Model: NewSLS50_52
This is one of the good ones. There are other brands just as good, and manny brands are worse, but this handles well, rolls down easily, doesn't come off at all easily, and adapts to dips and curves like a champ.
Appropriately heavy and dead, I'm happy with the way it smothers panel resonances and even at muffling direct sound, like a big hand over my Uncle Harry's eternally noisy mouth. You can rip the foil but you have to work hard at doing that.
Remember to buy a brayer; you can roll overlaps nice and thin. Also remember to pre-wipe the sheet metal with a decent solvent like acetone or Stoddard/Varsol. It should last forever.
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Reviewed in the United States on April 26, 2025
★★★★★ 5
Good stuff, but watch the temp
Model: NewSLS50_52
I used this in my single cab pickup truck (89 ford.) It only took half the box (10 sheets or 25 square feet) to do the floors, but I bought the big box because I plan to do the doors, back wall, and maybe the roof as well. One thing I learned is that the temperature matters when you’re doing the installation. It was around 55F when I started in the evening, and when it dipped down into the 40s the sheets would not stick to the metal, and were hard to compress with the roller. That’s why I ended up only doing the floors and not any vertical surfaces; i will have to wait for a nice hot day. The other thing is that the foil layer on top is razor sharp at the edges, definitely wear gloves! I didn’t notice until after but I have little papercuts all over my fingers. Aside from those things, the install was easy and straightforward. The sheets cut easily with scissors, and any goo that ends up on your hands or scissors can be cleaned up with acetone (nail polish remover), or lacquer thinner. I would use this stuff again.
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Reviewed in the United States on November 16, 2023
★★★★★ 5
Very efficient!
Model: NewSLS50_52
Amazing the difference it makes on dumping the noise. Very easy to install. Pell and stick literally! Great!
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Reviewed in the United States on November 23, 2025
★★★★★ 5
Cost effective
Style: 8.7 sqft（8 pcs）, Material Type: Aluminum 197 mil
Nice, cost effective material. It stuck nicely to the door and was fairly easy to use. The grid marks on the back made it easy to cut. I would not rank it up with other materials in sound and heat isolation, but it did cut down the overall vibrations on the door panels and I did not feel heat immediately from the floor area as i did with bare metal. If you are working with a budget and want modest improvement, this material will work well over most stock materials.
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Reviewed in the United States on June 7, 2026