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Description
Holley Terminator X MAX Engine Management Systems 550-928TERMINATOR X MAX MPFI W TRANS & DBW 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
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 550-928 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:
- 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, Drive-by wire throttle body control, 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
- Recommended Pedal part number - 10379038
- Includes: 58x/4x LS Engine Main Harness - EV6 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 assor
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, Drive-by-Wire, Transmission |
| Part Number | 550-928 |
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
4.7 ★★★★★
Based on 22 reviews
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Product Reviews
★★★★★ 5
Modern luxury with summer fabric that performs above its price!
Color: Beige, Size: 14, Color: Beige, Size: 14
Wow! My son wore it for Easter Sunday and this suit fits the bill! The linen material is spot on--not too heavy and not too light especially since the weather is warming up now. The jacket is quality made--the design is modern executive, the stitches are strong no flaws to note. The pants are tad bit longer but that's okay, build quality is also great. The white shirt is decent and matches well with the rest of the set. The bow tie and tie itself is a great complimentary to the set, though optional to wear. The whole set just has that quality you would really look for in the price range you would want to pay. Overall, best value for for the, wear right outside the bag, maybe a light ironing otherwise it's perfect! I highly recommend it, no complaints here very happy with this suit!
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Reviewed in the United States on April 5, 2026
★★★★★ 4
Heavy linen character, but a beautifully tailored suit!
Color: Beige, Size: 4, Color: Beige, Size: 4
This is a really nice linen suit! The jacket is beautifully made and well-tailored, with a fun speckled texture that has lots of pretty color variation (we ordered the beige). When I placed it side by side with a similar linen suit from another brand, the difference in the linen texture was really noticeable — this had a much stronger linen character that stands out!
It has three useful pockets on the outside of the jacket, which is great for little hands. The only downside is that one of the inside pockets is just for show (faux), which was a bit surprising and somewhat disappointing for my little guy.
The pants have pockets too, but they aren’t very deep — perfect for small treasures, but not much more. The pants are made from a lighter, thinner single-layer linen compared to the fully lined, double-layer jacket, which makes sense for comfort and easy movement.
The pants didn’t come with a front crease ironed in, so you’ll want to press one yourself. The linen did pick up some creases from being folded in the package, but it doesn’t seem quite as wrinkly as some other linen fabrics I’ve tried. Still, like most linen clothes, especially for boys, the pants will need occasional ironing to keep them looking neat and crisp, especially after a day of play and general wear. The structured, lined jacket stays looking smoother and more put-together with less effort.
It also came with a bow tie, a neck tie, and a tuxedo-style white shirt as extras. The ties aren’t great quality — they’d work fine for quick photos but probably won’t hold up to much actual wear. The formal white shirt feels a bit funny paired with the casual linen suit, but I don’t mind at all. We already have white shirts that we prefer, so we’ll use those instead. For us, the extras are really just bonus items we won’t plan on using.
Overall, it’s a handsome little suit that’s perfect for special occasions like weddings, family photos, or holiday events. My kid looked adorable in it! The stronger linen texture on the jacket gives it a premium feel that I really like. Just be ready for a bit of extra care with the pants to keep everything sharp.
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Reviewed in the United States on April 8, 2026
★★★★★ 5
Great suit set
Color: Light Grey, Size: 4
It is incredibly attractive and includes everything a young child needs for a special occasion.
The material is a 75% polyester and 25% linen blend, and the outer fabric feels remarkably smooth. Its unstructured design allows for an attractive, natural drape, and the blend conveniently allows for machine washing at home.
As is typical with linen-based materials, the fabric can be naturally stiff and prone to wrinkling, so I recommend ironing or steaming it before use. The lightweight feel makes it an excellent choice for the spring, summer, and fall months.
Overall, this suit offers exceptional value for the price.
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Reviewed in the United States on April 12, 2026
★★★★★ 5
Samsonite? I was way off!
Size: 8, Color: Light Blue, Size: 8, Color: Light Blue
Linen was a nice enough material and slightly distracted from the dumb&dumber blue motif. The regular suit material would have been a full homage. It is what he wanted so this was a fair compromise. Stats/ he is a size 8 in most brands, 51in and 60lbs. Purchased an 8.
A size 7 would have been a better choice and more tailored look but this fit fine in the important places and he has room to grow. Short notice, quick shipping and fair quality for the price. May your Harry Dunne love it as much as mine did.
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Reviewed in the United States on May 8, 2026
★★★★★ 5
Great price without skipping on quality.
Size: 12, Color: Light Green, Size: 12, Color: Light Green
Perfect for 8th grade dance. This 3 piece suit fit perfectly. It look so sharp for his dance. This would also be nice for a wedding. I plan on getting a few different colors the price makes it affordable but doesn't skip on quality.
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Reviewed in the United States on May 30, 2026