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MegaSquirt-III Daughterboard Kit
MegaSquirt-III Daughterboard Kit
MegaSquirt-III Daughterboard Kit
MegaSquirt-III Daughterboard Kit
MegaSquirt-III Daughterboard Kit

MegaSquirt-III Daughterboard Kit

5 out of 5 based on 2 customer ratings
(2 customer reviews )
MegaSquirt-III Daughterboard Kit



Upgrading your MS1 or MS2 to the latest MS3 has never been easier with this processor replacement! We’ve packaged the MS3 daughter board with 2 of the 40 pin sockets, so it will match up with our cases (required for upgrade) which have cutouts for the SD card and USB adapter.  Simply unplug your MS2 daughterboard and plug in the MS3, insuring there is a total of 2 40-pin sockets in between the socket on the board and the header on the MS3 daughterboard. If upgrading from MS1, you’ll also need to add the MS2 jumpers and may need to change some of your input and output pins. See this page for more information.  MS3 daughter cards are for use only with genuine Bowling & Grippo MegaSquirt mainboard PCBs, and is intended for use with the V3.0 and V3.57 boards. The MS3 daughter card on its offers these features:

  • VE and ignition tables are now both 16 x 16
  • 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

The MS3 also provides a starting point for even more expansion. You will be able to connect the pin headers on this board to additional hardware, such as the MS3X board or other cards to enable features like these:

  • 8 channels sequential fuel control
  • 8 channel sequential ignition control
  • Individual fuel and spark trim for cylinder by cylinder tuning
  • 2 and 3 channel PWM IAC control
  • 2 stage nitrous controller
  • Table switching for multi-fuel engines
  • 2 step launch control
  • And more!

For complete MS3 documentation, see

While the MS3 daughter card theoretically could be used on the V2.2 board, some of the attachment points to solidly mount the card are not there, and there is no off the shelf case or documentation for the combination of an MS3 on a V2.2 board. This combination is not recommended.

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2 reviews for MegaSquirt-III Daughterboard Kit

    Only logged in customers who have purchased this product may write a review.

    Do I need to order a daughter board kit if I am getting a MegaSquirt-III V3.0 kit?

    • The MegaSquirt-III kit includes this daughter board kit. The daughter board kit is for upgrading other MegaSquirt versions to MS3.

    Where is this made?

    • The circuit board is assembled in the USA.

    Questions & Answers

    1. 0 votes
      Q Would this work on an MS2 V3.57 Board? answer now
      Asked on March 20, 2018 9:13 am

      Yes. You will need to swap to the MS3 case as well.

    2. 0 votes

      The bare minimum would be to add an MS3 daughterboard and MS3 case. Adding the MS3X expansion card would be the easy way to get most of the extra I/O the MS3 processor allows.

    3. 0 votes
      Q Does it come with main drive or Chip answer now
      Asked on July 13, 2017 6:08 pm

      This has the processor chip that runs the MS3 firmware. The injector and coil drivers are on other boards. It's one of three cards that make up a complete MS3 - the other two being either a V3.0 or V3.57 main board, and an MS3X expansion card.