Originally Posted by guitar maestro
A few years ago I read an article where aside from the dwell time being limited, current is also limited by the pcm. ...
This is the waveform for a 2.3l ford dual coil setup:
This is what I was trying to say above; it ramps the current up to some value, based on the coil, and then dumps it, making the spark.
The pedestal length increases at lower rpm; the ramp is the shortest expected firing time, probably ~7k rpm. It can be measured with a scope.
If you put them in series, it really doesn't matter; they have the same current thru them; even in series, it never gets close to 12V at all.
The coils now are Current-fed, not voltage fed.
Big difference from the way a set of points worked them, lol.
The ramp in this graph would support 12k rpm.
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Last edited by Grog6; 06-07-2017 at 06:28 PM.