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New to the forum and MS

Posted: Sat Jan 03, 2015 6:45 pm
by Rockin C Racing
As the subject says, I'm new to this forum and MegaSquirt. A friend bought a MS1 v2.2 for a project back in 2004 and assembled it in 2006 according to his notes. His project never went anywhere and died as they sometimes do. I bought everything he had from him for a project that I have a couple of years ago. I'm now to the point of starting the install and wiring for my project. I just ordered some items that I was needing, but I'm sure I will have some questions to get it all hooked up correctly.

The project is a rear engine dragster with basically a small block chevy that was originally carbureted that I'm switching over to EFI. I have the fuel system all installed (fuel rails, injectors, throttle body, pump, etc.). As stated, I have a MS1 v2.2 and I also have the stimulator v2.1 and a relay board. The dragster already has a couple of relays, but to keep the MS safe and use of fuses, I plan on using the relay board and rewiring the existing fuel pump setup. The other items I will need to figure out and have started researching on the forum is wiring the MSD 7AL ignition and the MSD crank trigger. From what I can tell so far is that the MSD tach output can be used for rpm signal. As for the crank trigger, the signal from that I would guess would be used as the ignition input. I haven't downloaded the software and looked at it yet, but from what I've seen in posts would be to use VR for the crank trigger. Until I get my relay cable and various sensor connectors to wire up my wiring harness, I'm not in too much of a hurry. I'm only looking for injector control out of this setup.

Any information that you can add, confirm, or deny would be greatly appreciated.

Re: New to the forum and MS

Posted: Sun Jan 04, 2015 2:19 am
by trakkies
I'm personally not too keen on the relay board. It adds extra connections where not needed like in sensor circuits - and more important makes it more difficult to keep the power and sensor grounds separate. Of course you don't have to wire it exactly as its schematic shows, and just use the relays and fuses. But then you might as well just use individual relays and fuses.

It's well worth drawing out your own individual schematic. Which shows the actual wire colour you use. Will save a lot of head scratching down the line if you need to fault find or modify things. Something like this:-
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