MoTeC Global Forum

Hi All.

Nice to see a Motec board. I expect that it will be helpful.

Can anyone describe what can/cannot be accomplished using multiple ECU's tied together through the CAN bus?

I have an application that could benefit from the additional outputs.

Allow me to blow your cover:

Paul's one of the best best fuel Injector guys I've ever worked with. Having him on the board is a great resource.

-Neel

OK, cover blown...

I'll try to keep up with this forum and help with injector questions.

Thanks Neel

Anyway, any takers on the multiple ECU question? Anyone have experience with this?

Hello Gentlemen and welcome to our forum.

Basically we have had various engines that had too many devices to happily run on one ECU, the new BMW V10 M5 engine is a good example.

Effectively what we can do now is "slave" a second M400/M600/M800/M880 to a "master" via the CAN bus. The slave setup uses a fuel main table that simply says when the master is using 12.6msecs of fuel I will use 12.6msecs of fuel and similarly for the ignition. This means that you only have to tune one ECU and the other simply follows.

We currently have a few engine running like this.

Hi Paul,

I have used 2 M800s working together on several V10 and V12 engines, it can be very powerful. You can use any two (or perhaps more) M400,600,800 and use all outputs and inputs but tune it is if it was a single ECU. The ECUs are set up in a master slave configuration with each ECU taking care of alternating cylinders in the firing order. The master ECU is in control of both the fuel and ignition, it then sends its current fuel and ignition value via CAN to the slave ecu that then delivers the same fuel and ignition. When you tune the master ECU you in effect tune the whole system. You can also connect sensors to the salve ECU and CAN the channels back to the master ECU that can then use the sensor values as part of the fuel and ignition calculations.

This method can potentially give you control of 16 injectors, 12 ignition, 2 X drive by wire, and 4 X lambda as well as lots of other inputs and outputs.

Hi Paul,

i never in my life did put 2 ECU's togheter but welcome to MoTeC forum!

Cheers Pascal

Thanks all.

If i am to understand this correctly you can use any 2 of the x00 series ecus as master slave combo. Can you use a M880 and say a M600. ?

Robbie

Yes, that is correct, the CAN setup for multiple ECUs is the same for the M400, M600, M800 and M880 so do what ever combination you like.

Just a specific point though: This is for V and horizontally opposed engines where one ECU runs one bank and the second ECU runs the other. An M400 coupled with an M800 would be able to do a V8 and not a v12.