Explain a few things to those of us not so brilliant…
How exactly does the capacitor increase the intensity of the spark?
-See below.
If the capacitor is charged by the rapid field collapse of the coil windings, the spike of which is, say, 40,000 volts, does not the capacitor charge to 40,000 volts less losses?
-There will be no substantial loss since the capacitance is very low for the duration of the charge. The capacitor will charge to the same, say, 40kV.
Is the discharge rate of the capacitor quicker than the field collape of the coil windings around the coil core and subsequent induction?
-Yes, provided that the resistance of the discharge circuit is low, which is true for the non-resistor type plugs as in “DirectHits” or for “Pulstar” plugs where the condenser is positioned directly before the gap, that is after resistor in the plug.
How does delaying the voltage spike to the plug gap by introducing the delay of charging and discharging a capacitor enhance the combustion process?
The 100 pF is a low capacitance. The resistance of the wires and the coil itself will result in some delay for charging, indeed, but this delay will be negligible. Even 6000 RPM is very slow for 100 pF connected to a several kOhm resistor (typical resistance of wires and the secondary coil). This delay itself has nothing to do with the putative effects of the contraption in question.
The spark… is not the spark intensity a function of the gap size, the breakdown voltage of the matter in the gap, and the potential applied at the tips of the electrodes?
Not only. Make a spark by shortening a small 12V battery from, say, a portable radio and (please don’t) make a spark by shortening a car battery. Same potential, but the two can sustain very different amperage (the actual difference is in the internal resistance of the two: in the car battery it is much lower). And this is what matters. However, if you charge a condenser using the same small battery from the radio, the shortening the capacitor can prove itself quite an experience. In this case the amperage in the spark will depend on the resistance of the plasma in the spark plus the resistance of the wires going from the condenser to the spark.
Does not the resistance of the gap drop immediately as soon as the voltage energizes the fuel between the electrodes?
-The resistance of the gap does drop dramatically after ionization has occurred.
Assuming the capacitor cannot charge to a voltage any higher than the spike that charges it, and assuming both have an extremely fast discharge rate, how does the intensity of the spark become greater? Where does the added energy come from?
-Some extra energy comes during the extra time the coil has to work harder charging the condenser, the condenser stores it until it is essentially shortened by ionization in the gap (aka spark). But there is more (less?) to it than just energy: the discharge of the capacitor through a low resistance circuit happens very fast. If we define “intensity” as the maximum power developed in the spark, it will go up as the duration of the discharge goes down even if the total energy of discharge is the same, this one reason why the power can go up substantially when a condenser is attached. In reality, the energy dissipated goes up, too (see above), so the combined effect is even stronger.
-Bottom line: I’m sure you’ll get stronger spark, but, again, I’m not so sure it will help to achieve the advertised benefits as opposed to screwing up the way computer-controlled engine operates (the coil will behave differently from the standpoint of the controller when a capacitor is attached to the plug). Testing. Only testing can answer.