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  • crank trigger angle

    Just a tip for anyone setting up MS...

    My EFI Source Megasquirted car has ben running fine but we were back at the dyno yesterday playing aroud with it and it didn't really like to act right all the time. I had the pickup at 45 degrees so I moved it to 69 degrees BTDC and it made a huge difference. I guess it really does like the sweet spot of 60-70 degrees.

  • #2
    Re: crank trigger angle

    Originally posted by revolutionary
    Just a tip for anyone setting up MS...

    My EFI Source Megasquirted car has ben running fine but we were back at the dyno yesterday playing aroud with it and it didn't really like to act right all the time. I had the pickup at 45 degrees so I moved it to 69 degrees BTDC and it made a huge difference. I guess it really does like the sweet spot of 60-70 degrees.

    Below 20 degrees or above 50 degrees is where the trigger angle should be set - It's buried in the instructions somewhere...

    Matt Cramer can correct me if I am wrong (he's more familiar with the details of the MSnS firmware that runs on the EMS-pro) but, I believe it has to do with the way the software computes ignition advance: it's switching between methods whenever your total timing crosses your Trigger Angle. one mode is called "this cylinder" and the other "next cylinder" - at least, that's what I believe is going on! If the trigger angle is 50 degrees or more, you're not likely to ever run the engine with more advance than that (at decel, unloaded or light cruise on a street engine, perhaps).

    -scott
    www.realtuners.com - catch the RealTuners Radio Podcast on Youtube, Facebook, iTunes, and anywhere else podcasts are distributed!

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    • #3
      Re: crank trigger angle

      Scott is correct; above 20 degrees it is running in "this cylinder" mode. To see how this works, suppose you have the pick-up 45 degrees BTDC and the timing set to 25 degrees. It'll detect the pulse from the pick-up, calculate that there's 20 degrees between the pick-up and when to fire the coil, calculate how much time that represents, then fire the coil after that much time has gone by. If you're running more advance - like 40 degrees - the difference is only 5 degrees, and there isn't enough time to carry out the calculations so you don't get the full advance.

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