Product Summary

Universal Fit, 24x Crank Reluctor, 1x Cam Trigger

  • An on-board 1bar MAP sensor is perfect for N/A or Nitrous engine combos
  • The real-Time fuel map learn, takes the guess work out of tuning your base fuel table
  • Specifically designed for GM LS1/LS6 engines with 24x crank reluctor and EV1 Injectors
  • Features a single channel of wet or dry, progressive or non-progressive, rich/lean safeties, and target closed loop AFR nitrous control
  • Includes a 3.5" Touchscreen Handheld that contains a calibration wizard which allows you to quickly build a base tune for any LS engine
See more details

Key Specs

MFG. Part #550-903
BrandHolley
Ignition TypeFactory GM
Tuner StyleTouchscreen Handheld
Throttle StyleCable Driven
See more specs

Need To Know

Quick and Easy Returns

Return Policy

Holley 550-903 Details

Take control of your LS engine with Terminator X! 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 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. Terminator X 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 has the features and technology you need at a price that won't break the bank!

  • For GM LS1/LS6 engines with 24x crank reluctor - with EV1 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)
  • On-Board 1bar MAP sensor, is perfect for N/A or Nitrous engine combos. 
  • 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
  • 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.
  • 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!

Application

For GM LS1/LS6 engines with 24x crank reluctor with EV1 Injectors.

Charts

CARB Warning

For race/ off road use or for use on pre-1966 vehicles.

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

Holley 550-903 Specifications

KEY SPECS
MFG. Part #550-903
BrandHolley
Ignition TypeFactory GM
Tuner StyleTouchscreen Handheld
Throttle StyleCable Driven
GENERAL
Crank Reluctor24x
Cam Trigger1x
Injector ConnectorJetronic / Minitimer (EV1)
MAP Sensor IncludedYes
Transmission ControlNo
Oxygen Sensor StyleBosch
GTIN Code090127060797
Sold in QuantityKit

Ratings & Reviews

5

2 Reviews

Overall Assessment

Customers highly recommend this product for its quality and practicality, noting it as a reliable and trusted component in their builds. Our product also stands out in terms of easy installation, providing an intuitive 'plug and play' feature appreciated by many. In comparison, customers perceive it as superior for multi-car usage. Its unique qualities, easy accessibility and reliable performance makes it an excellent choice, prompting customer loyalty.

5

2 reviews

5

2

4

0

3

0

2

0

1

0

Filter by Ratings

I will for sure be buying more for my other cars

5.0

4 years ago

Easy

Solomon, ks

Verified

Great product and fast shipping.

Would Recommend

The Best and easy HOLLEY KIT ever, always trust what I purch

5.0

4 years ago

Slick

Westland michigan

Verified

I trust holley on any build I do,it's the easy plug and play I have seen in my life.i have ordered at least 2 of theses units in will continue to use your products available with easy access and help on demand. Love and keep up the good work.

Would Recommend

Showing 2 of 2 reviews

Questions & Answers

1 Question1 Answer

Can I run a turbo with this

by Red

2 years ago

1 answer

1 of 1 questions shown

Fitment

  • GM LS6

  • GM LS1

  • GM LS1

  • GM LS1

  • GM LS6

  • GM LS1

  • GM LS1

Customer Impersonation Script