The MegaSquirt EFI System is truly the dream Electronic Fuel Injection computer for the DIYer. MegaSquirt has been installed on thousands of engines from restored classics to daily drivers to full on race-cars. Turbo, supercharged, or NA the MegaSquirt can handle your fueling needs.

Features / Benefits of the MegaSquirt EFI System

  • Onboard MAP sensor for NA or boosted engines up to 21psi!
  • Speed density or Alpha-N.
  • Use High Impedance Injectors or Low impedance with resistor pack inline
  • Compatible with output from narrowband sensors and wideband O2 systems.
  • Log data on your laptop for later analysis.
  • Tuning software is free for download and regularly updated with new features.
  • Open Source design - all code and hardware information is available online.
  • Includes proper female DB37 connector and shell for your wiring harness.

Additional Features

  • Professionally Machined Brushed Aluminum Endplates. Excellent Fit and Finish!
  • Flanged ends for easy mounting.
  • The crystal is glued in place to reduce sensitivity to vibrations.

The Kit it self

  • MegaSquirt programmable EFI Engine Management System from Bowling and Grippo.
  • Install fuel injection on anything from a single cylinder lawnmower engine to a fire breathing V12, and anything in between!
  •  This kit is easily the biggest bang for the buck in the standalone EFI arena.
  •  You build it, You tune it, you drive it.
  •  The sense of accomplishment is amazing as are the results when you finally get your car dialed in just right after spending who know how long messing around with piggybacks and other 'hacks' that just don't get the job done right.
  •  Stop wasting time and money and MegaSquirt your ride! You won't regret it.

    This kit includes everything you will need to build your MegaSquirt ECU. Just add tools, solder and time! (Case is included ******EVERYTHING is include to build the ECU)

MegaSquirt Wiring Harness – 3.6 meters

IAC and Ignition wire have been added for MS-I / MS-2 use or MS-3 Primary Harness Use

  • 12' of TXL High temp automotive grade wire.
  • Color coded wiring with labeling printed on the wire every 3 inches -- no paper tags here!
  • Shielded Ignition input wire to cut out interference
  • All wiring is pre-crimped (NOT solder cupped!) to the DB37
  • Heavy duty AMP metal DB37 hood for superior RFI/EMI shielding (no cheap plastic 'metalized' hoods used on our harnesses)
  • Wiring diagram included (pinout below)
  • Simply the best MegaSquirt harness available anywhere, at any price


Note that the Wiring Harness and Relay Cable are 'mutually exclusive', meaning they are not designed to be used together. If you are using the wiring harness then you are wiring everything directly back to the DB37 on the ECU with relays and fuses where needed. If you are using the Relay Cable you are connecting the DB37 on the ECU to the Relay Board directly (so there is nowhere to plug the harness in anymore) and you then wire everything directly to the screw terminals on the relay board.

MegaSquirt Relay Board - Assembled Unit Part # MSRelay-C

Though the Relay/Power Board is not required, it is a convenience and reduces the chance of miswiring during the installation. The relay board provides a central place for all of the required relays, fuse protection, and external wiring for the MegaSquirt ECU. If you are installing MegaSquirt in a previously fuel injected engine you may be able to reuse all of your existing relays. If you are fuel injecting a previously carbureted engine you will need to install relays for the main ECU power, Fuel Pump, and FIdle circuit. You can do this manually or you can use the Relay Board to simplify this process. Comes with DB-37 connector to be used to build your relay cable, and the "half-case" shown in the picture. The parts on the relay board are capable of standing up to an underhood environment.

MegaSquirt-II Daughterboard

For upgrade of your Megasquirt-I ECU, or replacement of your damaged MegaSquirt-II daughterboard

This is the latest version of the MegaSquirt-II daughterboard with the C64 processor and is CAN-enabled. The latest embedded code can be found here:


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