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Description
Holley Terminator X MAX Engine Management Systems 550-926TERMINATOR X MAX MPFI W TRANS & DBW, 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 & DBW, 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 550-926 also has 4L60E or 4L80E Transmission control and Drive-By Wire Throttle Body 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, and drive-by wire throttle body control.
- 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
- Recommended Pedal part number - 10379038
- Includes: 24x LS Engine Main Harness - EV1 Injector Harness - DBW Throttle Body 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
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, Drive-by-Wire, Transmission |
| Part Number | 550-926 |
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
4.1 ★★★★★
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Product Reviews
★★★★★ 5
surprised!
I actually didn't realize I had ordered "time released" version. I thought these were just normal melatonin. But now that I've tried these, I love them so much better than the regular version! Helps me sleep better through the night. No taste, love this brand of Source Naturals.
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Reviewed in the United States on October 17, 2025
★★★★★ 5
The only one I'll use!
As the title says, this is the brand to get!! It's fast-acting, doesn't give me weird dreams like some do, and I never wake up feeling groggy.
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Reviewed in the United States on March 13, 2025
★★★★★ 5
Works wonders
I've been buying these for well over a year now as Subscribe and Save. I work 12 hour overnights as a nurse. My sleep schedule normally gets messed up. I would have no problem falling asleep but would wake up only a few hours later which is not good when you have work again that night. We buy these on Amazon due to the great price and the fact that they are extended release which helps keep me asleep longer. When I take 1 or 2 of them, I am able to sleep about 7-8 hours which is great. I take this both when I sleep during the day and sleep during the night. It helps me sleep no matter when and I am able to adjust my sleep schedule often. I have recommended them to many.
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Reviewed in the United States on January 10, 2013
★★★★★ 4
Works quite well, dose still a bit high for me
Used to take the Natrol 5mg slow release, now that I can compare these 2, I love this more. It doesn't make me feel too edgy, it's quite relaxing actually. I still have to halve the dose as the full dose makes me groggy the next day. Where the Natrol gave me very vivid, but not unpleasant dreams, these don't make me dream as vividly. It does take a bit longer to get me to sleep, but once asleep, your asleep. Highly recommend, once I finish this bottle, I'd get the 2mg tr next time, as a lower dose works better for me.
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Reviewed in the United States on July 10, 2014
★★★★★ 5
Excelente Muy Satisfecho
Servicio excepcional, cuidadoso, el producto muy bien empacado. Y el tiempo de entrega fue el acordado. Y del producto ni hablar, excelente.
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Reviewed in the United States on February 3, 2026