/// ECU Selection Guide

Many of our customers are unsure which MegaSquirt hardware version is right for their project. We've written this guide with the hope of helping to stem some of that confusion, and potentially help you save some money.

You need the v3 PCB if:

  • You plan to drive a coil without any external modules (MSD 6A, Bosch ICM, etc)
  • You plan to drive more than one coil, or run wasted spark
  • Your engine has a VR sensor that you plan to use for RPM Input
  • You plan to run low impedance injectors
  • You plan to add any additional output circuits (fan control, nitrous, water injection, etc)

Main Features of the v3 Board:

  • Higher quality PCB means means less chance for onboard component failures
  • Onboard current limiting helps keep power surges from damaging the ECU
  • Output drivers have an onboard heatsink to minimize component failure even during the worst conditions
  • Seperate power and ground planes on the PCB help to eliminate internal noise
  • Capable of driving up to 4 coils (4 cylinder coil on plug, or 8 cylinder wasted spark)
  • Onboard support for 20psi boost
  • Upgradable to 45psi boost sensor with realtime barometric pressure compensation

Additional Benefits of Using the MS2 Chip with the v3 Board:

  • MS2 -extra code is much better at closed loop controls needed for daily driving
  • Significantly higher resolution for fuel injection and ignition timing
  • Chip has onboard provisions for running optional outputs - this leaves more room for further expansion
  • Onboard stepper motor style idle valve control
  • Output test mode makes installation troubleshooting easier

Also consider a v3.57 board (with an MS2 chip):

  • You aren't planning on controlling more than one coil
  • You want the most robust board hardware, and are planning on a PWM idle valve
  • You don't anticipate your configuration changing dramatically once it's up and running

There is also the option of going with the old/original v2.2 MS board - it has a lot of limitations with regards to spark output and RPM inputs, but is the ultimate budget configuration if your setup allows working around its limitations. We can set up one of these with an MS1 chip for $250, though for anything that is street driven we recommend the MS2 as a minimum.

For most new installations, we recommend the v3 board with MS2 chip, as it provides all of the required area for future circuit upgrades, as we find most people normally want to continue expanding their project. It also allows for easier troubleshooting if something does go wrong. As we've found lately, more and more people are begining to use the MegaSquirt to run wasted spark configurations with a factory trigger wheel and VR sensor, both of which lend themselves well to starting off with a v3 board.

The v3.57 board, which we only sell with the MS2 chip, is a great option if you've got a single coil and want a robust daily driver setup that will use an idle valve, but not need a lot of extra outputs.

Consider an MS3 ECU:

  • Budget is less of a concern
  • Want the latest and greatest code, with ongoing improvements as the developers continue to release new versions
  • Need the extra I/O provided by the MS3X daughter board (up to 30 various inputs and outputs!)
  • You have a lot of injectors to control, dual injector configuration, or are running sequential injection

We've started using MS3 ECUs on more complex setups now, as it provides a great basis to build on using the latest code. But the drawback is cost - it is a bit more expensive. We don't list specific prices for the MS3 ECUs as they are a lot more configuration dependant. If you're interested in an MS3 ECU let us know what you're working on and how we can help configure it, to give you a better idea of cost.

Finally, for more information on the differences and features of each board version we encourage you to visit www.megamanual.com along with www.msextra.com/manuals. There you'll find a wealth of knowledge from the creators of MegaSquirt, as well as the code writers for MS-etxra code, as well a more specific details on each version of chipsets and main boards. And again if you have any questions on a specific version, feel free to reach out and we'll help however we can.

/// Order

Each ECU is custom built for your application. When you're ready to order, send us an email at sales@spitfireefi.com with which ECU you've selected and information on your setup, including: Motor type, ignition type, number of coil drivers, etc.

/// MS2-extra ECU

$450 - Shipped

  • More Fuel/Timing Resolution
  • Larger Fuel Map
  • Better Closed Loop
  • Best Trigger Wheel Support

Visit www.megamanual.com for more details.

/// MS-1 v3.0 ECU

$385 - Shipped

  • Onboard Spark Drivers
  • VR Signal Conditioning
  • Low Impediance Injectors
  • Expandable Outputs

Visit www.megamanual.com for more details.

/// MS-1 v2.2 ECU

$250 - Shipped

  • Most affordable MS ECU
  • Drivers for External Spark Modules
  • Hall Sensor RPM Input
  • MSnS-Extra Code Compatible

Visit www.megamanual.com for more details.

/// Tuning and Install

Need help installing the ECU?

Not sure how to tune your engine?

We will install and tune everything we sell. If you're in Northwest Washington, drop off your car and we can do everything from tuning to a complete custom wiring harness.

Tuning and Installs