Major update of all my Help files and Manuals (December 2014) See HERE

Engine Management Systems by ExtraEFI.co.uk


For YouTube videos click here

For more information:

  • See the ECU price page
  • See the Frequently Asked Questions section
  • Take a look at the support and help files page
  • Every ECU package sold includes:

    • A fully labeled/ colour coded wiring harness (approx. one meter)
    • An RS232 communication cable
    • Tuning software, drawings and various manuals

    Up to four of the following features can be added to the MS1, MS2 or the MS3:
    (Please note that the MS3 can have an MS3X card adding which gives all sorts of inputs and outputs, etc, click here) for details

    • # Nitrous control
    • # 400KPa (38PSI) MAP Sensor
    • # Switchable Map Tables for Fuel or Spark or Both
    • # Boost Control
    • # (Closed loop is Experimental Code)
    • # PWM for Water injection control (MS1-Extra only)
    • # Dual O2 Sensor Support
    • # Shift/Warning Lights
    • # Launch Control/Flat Shift
    • # Real-time Barometric Correction
    • # Upto four Programmable Outputs
    • # Knock Sensor Input
    • # Tacho Output for coil pack use (Standard fit to most of my ECU's, see descriptions)
    • # Mass Air Flow Meter for Fueling Calculations rather than MAP or TPS

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I have been building MegaSquirt ECU's since 2003 and I'm one of the team who wrote the MS-Extra Code.

So you can rest assured this is THE place to purchase your MS ECU, with the knowledge that you will be getting what you need, rather than what someone wants to sell you.

No other MegaSquirt sales website comes close to this one for information, knowledge and backup of MS ECUs!

Everything you need to know is on this site, that includes video help files! If you still have any questions then I can answer them due to my experience with the actual firmware the ECU's run and with the years of experience I have building, tuning and testing them!

ExtraEFI was setup in 2005 with a simple aim; to supply fully assembled, tested and warranted MegaSquirt ECU's to a very high standard.

All my ECUs run the latest version of the MS Extra code. Well, they would do, as I'm one of the authors of the MS-Extra code and author of the MS1-Extra and MS2-Extra manuals.

MegaSquirt is a standalone DIY mappable Engine Management System that can control the fuel and spark or fuel only or spark only on virtually any liquid fueled spark-ignition engine, naturally aspirated or boosted.

Are you still confused about MegaSquirt? Click here.

A MegaSquirt ECU can give you mappable fuel and or mappable ignition using:

  • A distributor setup with a simple hall sensor/points in the distributor or a cam/crank signal.
  • A coil pack setup using a variety of cam/crank signals.
  • A Coil On Plug setup using a variety of cam/crank signals.

All of the ECU's I sell have the MS-Extra code loaded into them, these are the features that come as standard:

  • # 16x16 Fuel table
  • # 12x12 Spark table
  • # Rev limiter
  • # Overboost protection
  • # Mappable Air Fuel Ratio targets
  • # Wide Band or Narrow Band
  • # Coolant temperature related ignition timing advance
  • # Inlet Air temperature related ignition timing retard
  • # Manifold Absolute Pressure rate of change or Throttle Position Sensor rate of change acceleration enrichment
  • # Overrun fuel cut
  • # Hybrid Alpha-N
  • # Staged Injection
  • # Built-in Air Density Correction
  • # PWM Idle Control valves
  • # Stepper Motor Idle Control Valves
  • # Fuel and Ignition or Fuel Only or Ignition Only

I hope you find this site a good source of information. I am constantly updating the site, especially the Support page, so please check back every so often.

The files on this site (downloads page) are obviously free to all in the true MegaSquirt spirit, but bare in mind they are to be used at your own risk.
If you are in any doubt simply e-mail me.

The base configuration files are also there for you to try at your own risk, these are from people who have bought MegaSquirt's from me and have kindly sent me their finished files for others to benefit from or they are base files I have made to get people started.