Sorry, I cant leave well enough alone...
To jump a gap, the there is a certain required voltage you must achieve PER INCH OF GAP AT ONE STANDARD ATMOSPHERE! Look at that really close and see all the moving parts. Bacially, anything you do that puts more air molecules in the "gap" will require more voltage to create an arc. So, for instance, if you had your spark plug in a slight vacumm, you would need less voltage to jump the gap than if it were in 10PSI of pressure. the more PSI of pressure would in effect put more air molecules in the gap, which would require more voltage to overcome and produce an arc. Likewise, if you were to hold the pressure constant but increase the gap distance by adjusting the electrode, you would also be putting more air molecules in the gap, which would require more voltage be produced by the coil to create an arc.
So, to achieve a proper spark, you must have a coil that can produce more voltage than the boost pressure and plug gap could ever require. If you get blow out, then you must reduce boost pressure or spark gap, or switch to a more powerful coil that can create more voltage.
see how that all works now? That is why a coil that misfires under load would be just fine and dandy during normal driving.
thank you have a nice day.
