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New -10% Terminator X MPFI Kit for GM Gen V LT4 Engines

Terminator X EFI for GM GEN V LT4

This EFI System is specific to the LT4 version of GM's GEN V LT family of engines. Holley also offers a Terminator X system specific to the LT1.

What's Terminator X?

Holley's Terminator X family of EFI Systems are standalone engine management systems that closely replicate some of Holley's most advanced engine management systems but at a much more budget-friendly price. This PDF gives a highly detailed comparison of the Terminator X and X Max to engines built using the Holley HP and Dominator ECUs. To summarize, Holley was able to leave out some features found to be less-necessary by the majority of users and, in doing do, slash the price of a full-featured EFI System by half.  If you're switching your carbureted engine to multi-point EFI or are swapping a fuel-injected engine into your ride and need to stay on a budget, this is the EFI system for you.

Here are some of the features that are included in each Terminator X kit:

  • *Requires hardware not included with Terminator X system to implement
  • **X Max Version Only

Different Terminator X EFI Systems For Different Applications

Yes, there are quite a few different Terminator X MPFI Systems--over 100 with more on the way.  All Terminator X systems include either a Terminator X or Terminator X Max ECU. The Terminator X Max ECU provides connectivity for transmission control and drive-by-wire harnesses and is included only in those kits that require one or both of these features. Both ECUs include an on-board 1-BAR MAP sensor or you can add an external MAP sensor for boosted applications. On-Board Diagnostic LEDs display the status of ECU Power, Engine Run, Wideband Status, TPS Calibration, Crank Signal, and Cam Signal

In addition to the ECU the kit all Terminator X / X-Max systems include the following:

  • ECU Power Harness
  • Application-Specific Main Harness
  • 3.5-inch Touchscreen LCD Display with Setup Wizard app
  • Custom 4-input / 4-output harness pre-configured for two Electric Fans, A/C Kick, and A/C Shutdown
  • Bosch LSU 4.9 Wideband O2 Sensor

Unique To The Terminator X MPFI Kit for GM GEN V LT4 Engines

Holley provides many features unique to the GM GEN V LT Engine that make this EFI system a breeze to install and configure and powerful to operate.

  • Direct-fit connectors for factory sensors and injectors
  • Connector for factory ignition coil sub-harness
  • Controller for GM Gen V LT Variable Valve Timing (VVT) and Gasoline Direct Injection (GDI) control
  • Transmission harness for GM 6L80E and 6L90E transmissions*
  • Drive-By-Wire harness for GM LT DBW throttle body*
  • *Transmission Control Versions Only
  • *Drive-By-Wire Control Versions Only

Choose From Different Versions of the Terminator X MPFI Kit for GM Gen V LT4 Engines

Part NumberManuf.Engine / Fuel Pr SensorECUTransmission
550-1623GMGen V LT4 / Early (4-Pin)
550-1633-6GMGen V LT4 / Early (4-Pin)
550-1624GMGen V LT4 / Late (3-Pin)
550-1634-6GMGen V LT4 / Late (3-Pin)
  • *GM 4L60E(Pre 2009) through 4L80E Transmissions. Contact us if you have another.
  • **DBW throttle body and pedal not included.

What Else Will I Need?

Required:  EFI Fuel System with

  • EFI Fuel Pump (Many great options here)
  • Pre- and Post-Pump Filters
  • Fuel Pressure Regulator
  • Associated Hose, Hose Ends, Clamps, Adapters, Etc.


Not Sure? Review this product documentation before you buy!

Quickstart Manual
Holley Terminator X and X Max EFI Systems

Tuning Manual
Holley Terminator X and X Max EFI Systems

Installation Manual
Holley Terminator X and X Max EFI Systems for GM LS & Truck Engines

Wiring Diagram
Holley Wiring Harness for GM LS1, LS6, and 97-07 Truck Engine

Boost ControlYes (Requires Additional Hardware)
DIS OutputsEight
FamilyTerminator X
Fueling StrategySpeed Density, Alpha-N, or Combination
Includes Power HarnessYes
Injector DriversEight High Impedance
Internal Datalogging4GB
Nitrous ControlYes (Requires Additional Hardware)
Number of CylindersEight
User Configurable I/OYes
User-Selectable MAP StorageNo
Water-Methanol ControlNo
Displays And Controllers
Auto BrightnessNo
CAN Bus CapableYes (Specific to Holley ECUs Only)
Case/Bezel FinishBlack
ConfigurableMonitor dozens of pre-configured metrics provided by the ECU, including sensors, air/fuel ratio, switched outputs, drive-by-wire data, and more.
Data LoggingYes
Display TypeLCD
FunctionsSetup, Monitor, Tuning
Gauge/Display Size3.5 Inch Rectangular
Internal StorageYes (SD Card)
Harness TypePower Harness, Main Harness, Injector Sub-Harness, I/O Harness, Ignition Adapter. Transmission Harness (Transmission Control Version Only), DBW Harness (DBW Control Version Only)
Crank Timing
Sensor Harness IncludedDirect-Fit Connector to Factory Crank Timing Pickup
TypeECU-mounted 1 BAR MAP, Wideband O2
Also IncludedGM Gen V LT Variable Valve Timing (VVT) and Gasoline Direct Injection (GDI) Control
ApplicationGM GEN V LT41 Engines (Early and Late)
Emission Code3 - This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles and Racing Use Only Vehicles.
Unit of SaleKit

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Terminator X MPFI Kit for GM Gen V LT4 Engines

  • Views: 1855
  • Brand: Holley EFI
  • Product Code: 550-1623 | 550-1624 | 550-1633-6 | 550-1634-6
  • Availability: In Stock
  • $3,112.00
  • $2,799.95

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