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boosted79 boosted79 is offline
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Join Date: Jan 2015
Posts: 1,335
Thanks for the responses but I'm talking about misfire due to incorrect phasing between the rotor and the tower terminal after timing is pulled with the msd box. It depends if the dizzy is firing on the leading edge or the trailing edge of the rotor. If the dizzy fires on the trailing edge of the rotor at what you have it locked at (say 35*) then when the box pulls timing as boost comes up the rotor is going to be even further away from the tower terminal. That can lead to misfires because of the increased gap between the rotor and the tower. With forced induction you want your hottest spark at max boost. So that means you want the rotor terminal directly across from the tower terminal (minimum distance) when the MAP is seeing max boost. On the big Detroit caps you can drill a hole right next to the #1 tower and put a timing light on it to see where the rotor is firing in relation to the tower. Since these boxes can only pull timing you want your phasing so it fires on the leading edge of the rotor then when it pulls timing at max boost you want it to fire when both the rotor and tower are lined up, that means minimum distance and hottest spark. But you need an adjustable rotor to change phasing, not sure any are available for these? I'm a ways from getting into this on mine but when I do I'll buy a new cap and see if I can cut a window in it to see what's going on. There may be a way to either adjust rotor or cap if necessary.
Old 06-20-2017, 08:30 AM
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