I know Ive mentioned it before,but the perfect tune with any one ignition system wont be correct when you plug in a different one. But even perfectly tuned,most guys cant feel a ten hp difference . If you have a lean or rich condition and put a better ignition system on something that was marginal before it will change.
If you have an ignition that pulls dwell,tune around it,then change to a system with a better dwell curve you will need to change things. Its the same thing I see with guys going to an MSD and not seeing a difference. Or an out of the box carburetor. Things need to be tweaked to get the most out of them.
Everything I test gets run through the wringer. I keep coolant and oil temperature within a couple degrees use the same fuel,and test several times to make sure its not an anomaly .
I realize not many guys can do that,but I try my hardest to give guys good fact based information .
Keith