The box gets the signal from the distributor.
The box interrupts power to the coil.
Coil field collapses and the energy it contained is sent out to the spark plug, through the distributor rotor and cap.

That is the essence of any spark box that isn't a CD box.

The only thing that could differ is how long it takes for the box to decide to stop power to the coil. Everything else happens just the same as in a points distributor.

It has been my suspicion all along that the electronics in the RNN are quite a bit faster than in the OEM boxes or stock replacements. I believe when a board member was researching the transistor on the stock-type boxes that he said it was a pretty slow transistor. So brand-new electronics could be reducing the lag time between signal and result, causing the engine to have a spark earlier (more advance).

The only other way I could see this happening is that the box calculates when to fire the NEXT plug based on the signal from the previous cylinder. However, neither of these guesses involves anything associated with engine vacuum.

Therefore, I suspect the instruction to not use vacuum advance is the lazy man's way to tell us to recurve the distributor based on the quicker operation of the RNN.

Bolstering my description of the workings of the RNN is the initial advertising blitz touting horsepower gains in double figures, just by installing a different ignition box. I acknowledge that in some cases with highly tuned engines, a different spark box might increase power. But the engines they cited were not highly tuned racing engines.

The easiest way to show a hp gain from a box which one knows to operate more quickly is to perform the baseline test with the ignition timing backed off or retarded from the max power advance. Then the quick box electronically advances the ignition event and the power is restored.

I've said this all before, as some of you are grumbling right now. So maybe this is for the lurkers or newbies. You others can run along.

Finally, I have NOTHING against the Rev-N-Nator. I applaud the determination to produce a stock appearing ignition box for a limited market, that contains quality components. I hope everyone reading this post will go out and buy TWO, so we can keep these guys in business.

R.