MegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled Unit
MegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled UnitMegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled UnitMegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled Unit

MegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled Unit

5 out of 5 based on 8 customer ratings
(8 customer reviews)


In stock

SKU: MS3X357-C_BL Category: Brand:

Product Description

Complete, ready to run MegaSquirt-III ECU with the MS3X expansion board. 2.5 bar MAP sensor is standard equipment.

The MS3 daughter card on its own will give you all these features and more:

  • VE and ignition tables are both 16 x 16 with full interpolation.
  • 0.1% steps on VE table, 0.1 degree steps on ignition table
  • Socket for an onboard SD card – no laptop required for data logging  (SD Card not included)
  • Built in USB port
  • GM stepper IAC control
  • Closed loop idle and mixture control
  • CANBus communications for interface with GPIO Board, IO Extender, or other devices
  • Staged injection
  • Native support for many different OEM trigger patterns

This MS3 EMS already has the MS3X expansion board installed, enabling the following features:

  • 8 Sequential fuel injection outputs. Each can drive a high impedance injector, and unused injection outputs can be put to other purposes.
  • 8 Logic level 5 volt ignition outputs. Works with many types of ignition modules and coils, including LSx coils and our IGN-1As. Requires external module or coils with internal ignitors.
  • 6 Medium current outputs. Use for 2 stage progressive nitrous, boost control, tach output, 3 wire idle speed control, general purpose PWM or relay control, or many other potential applications.
  • 3 Analog inputs. Use for an external MAP sensor, second O2 sensor, fuel pressure, accelerometer, or general data logging.
  • 4 Switch inputs. Can be used to start data logging, arm a nitrous system, switch tables, launch control, VSS input (Hall sensor or VR with external conditioner), and more.
  • 1 Cam sensor input. Can be used with VR, Hall, or optical sensors.

The MS3X has all these circuits on it, just ready for you to wire up and use them. No mod kits, no setting up custom special order ECUs, just plug in and enable it in TunerStudio.

For complete MS3 documentation and more see

8 reviews for MegaSquirt-III EMS System with MS3X Expansion V3.57 – Assembled Unit

  1. 5 out of 5


    Well this is just great. I remember making fun of megasquirt maybe 10 or so years ago. Now it’s just simply a beast. I run this in conjunction with a stock 2jz is300 ecu so I wired in one thing at a time progressivly using more and more features from the megasquirt. Combined with tablet tuning, custom tablet gauge layouts, auto tune, ability to use any kind of sensor inputs, and all kinds of tuning options this is really impressive. Dollar for dollar it puts other Ecu’s to shame. If you can deal with the diy type of install then there’s really not a better deal on the market.

  2. 5 out of 5


    I purchased this unit, added the Mapdaddy 4 Bar Map sensor and Realtime clock. I had the unit in a couple weeks and had the car running a couple weeks after that. Granted, this was just the first build and a year later I have redone things a few different times (trying to clean up the factory wiring).

    Email support has been great plus the good support at MSextra and Corral have made this a very good experience. After-market ECUs are a lot of work and I have learned a lot about Engine Management from what I have done.

    This system replaced an Accel Gen 6 ECU that quit working. I’d recommend this system to anyone who wants to isn’t scarred about learning new things and will spend the time to make the most of their engine through proper management

  3. 5 out of 5


    quiero comprar un megasquirt para un motor ls 6.0 chevrolet no mas para instalar cual sería el mejor

  4. 5 out of 5


    Si señor la ms3 te sobra es mas te podría decir que es mucho ya que varias cosa quedarían sin utilidad en ella, particularmente en ese modelo que no tiene distribución variable ya con la ms2 estas bien sobrado.



  5. 5 out of 5


    La daughter Zeal Engineering Daughterboard with Dual VR Conditioners leer el manual de MSextra y mucha paciencia.

  6. 5 out of 5


    Cualquier megasquirt te funciona 1,2 o 3 en tu corolla

  7. 5 out of 5


    Yo quiero montarla en mi rx7 turboII que necesito.

  8. 5 out of 5


    Yo quiero saber si me funciona y que necesito para montarla en un corolla 95 con motor 1.6
    La mega squirt III

Add a review

What harness do I need with this?

  • You need both the MegaSquirt harness and the MS3X harness.

What inputs and outputs is the MS3 V3.57 with MS3X set up for?

  • It is set up for sequential fuel control and eight channel logic level spark output, with the following inputs and outputs:
    • Coolant temperature
    • Air temperature
    • MAP sensor (built in)
    • Throttle position sensor
    • O2 sensor - narrow band or external wideband controller
    • Crank and cam position sensor input - Hall, optical, or VR
    • On/off, stepper, or PWM idle control - unused idle control outputs can be repurposed as general purpose relay control outputs
    • Fuel pump relay
    • Eight fuel injector banks plus two fuel injector outputs for a second stage or general purpose outputs
    • 3 analog 0-5V inputs
    • Flex fuel input
    • 6 on/off or frequency inputs
    • 0-12V tach output
    • 5 general purpose on/off or PWM outputs
    • 8 5V logic level spark outputs
    • CANbus

What firmware does it have?

  • The MS3 V3.57 ships with the latest MS3 code. The code it initially shipped with will be indicated on a sticker on the underside of the unit.

Is the V3.57 board available in kit form?

  • The V3.57 is essentially a V3.0 that has been changed for machine assembly with very few differences. Consequently, it is not offered in kit form.

What connections are on the DB15?

  • By default, it only has a couple extra reference voltage and ground pins for sensors. The DB15 can be used for adding optional I/O if you run out of pins on the main connector.

Where is it built?

  • The components are assembled at various locations in the US, with final assembly completed in Suwanee, Georgia.

What is the warranty?

  • We provide a one year limited warranty against manufacturing defects.