The hand drawn curve is not meant to be precise but more of a concept or an example or close approximation for discussion purposes.
The total curve will be different (at idle anway) and thats my point.
The centrifugal advance portion of the curve is dictated by the springs of the distributor. B But they will and should have different curves and again thats the point.
With Manifold vacuum advance at idle I am able to achieve a higher idle advance without having too much at WOT or under acceleration causing detonation. And in my case can lower to a more retarded state if needed.
Also at t=0 seconds ie start of cranking there is little to no vacuum to speak of until just before ignition. So the cranking advance should be low aiding starting and idle capability which is another advantage of MVA. Right?
Again this is my concept and I am throwing it against the wall here. This is what I am thinking.
Does this make sense? Does anyone believe what I am saying is incorrect?