Msd (may Die Suddenly) Pro Billet Distributors. What Are Your Complaints?

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by larrym1961, Sep 20, 2013.

  1. I could be wrong, but I don't think the cam synch has anything to do with how the box controls ignition. I don't run a cam synch, at the moment, only a crank sensor.

    Whoops... rotating the distributor would only affect the cam synch... the crank sensor would have to be adjusted too, but you get my point, I think. My question still remains. The point I'm considering is whether it all works out to the same tune, even if the numbers on the screen are off.
  2. On a similar note, I'm honestly confused as to why it needs a cam synch. I'm surprised it can't make all of the adjustments from the crank sensor. If it knows to fire the spark once every 2 RPM, it ought to know when the injectors are firing in relation to the combustion process.
  3. This i s a speed density system, with sequential injector firing. This is not a mass air system. The cam sync has everything to do with sequential firing of the injectors. The Classic FAST was a bank/batch fire speed density system that did not use the cam sync, the TFI distributor was used as it was, as a distributor of spark and timing control.. With sequential injector timing, the dist. is used, and must be used as a cam sync sensor for the calculations to be made for ignition timing and injector firing. If this does not make sense, please call Brian Macy at Horsepower Connection. He is THE MAN when it comes to how and why the FAST XFI system works. By the way, the FAST still has to use a MSD ignition box, or something similar to run the ignition system. The FAST just tells the MSD box what to do and when to do it, it is not an ignition box in of itself.
  4. Your XFI and my BS3 are very similar. I think the developer of the BS3 had a part in developing that system too. I am aware that the cam synch controls the injector timing, but that the crank sensor controls the ignition timing. I know this because I run no cam synch with bank to bank, and my ignition timing works just fine.

    I was just speculating on why the thing was designed this way. Sorry my comments were not well enough articulated.
  5. No is easy to read more into a post than what was meant. And I do not know why it was designed this way, hell I have a hard enough time understanding how to make it work, let alone why it works the way it does.
    FastDriver likes this.