As you increase the ohmic resistance of the sparking system,
either by adding a resistor to the spark plug
or adding resistance to the wire,
the “burn time” of the spark increases.
Having a very intense spark with high current but for very short time,
by experiment has been found to result in more “misfires.”
Lowest misfire rate happens at the compromise where the spark intensity is “good enough” and when the time the spark endures is relatively long,
by experiment has been found to result in lowest possible misfires rate,
At high rpm a single coil does not have time to “recover” before the next cylinder fires.
Misfire rate at high rpm can be reduced at by having a coil for each cylinder.
Misfire rate can be further reduced by having two (or more) spark plugs per cylinder, each with its own coil.
( 5.7 Hemi set up)
Seems excessively crazy,
but an MIT student wrote his Master’s thesis about finding how many spark plugs per cylinder were needed to reduce the misfire rate to zero.
He got up to 16 spark plugs on a single cylinder and was still finding improvement.
The single cylinder, variable compression ratio, side valve design, CFR engine he was using has a combustion chamber design that lacks modern “overhead valve” engine design with quench, swirl, or tumble.
Your MIT example negates your increased resistance claim.
As you add resistance in parallel ( more plugs in this case) over all resistance drops.
You need to cite both claims to make a coherent conclusion.
And bet he never built a race engine and did dyno testing to prove or disprove his findings
The Master’s student did have a dyno measuring the output of his little CFR engine with one cylinder and whose side valve head design is about as far from “modern race engine” as one can imagine.
The idea that he was also so clueless that he hooked up 16 spark plugs to a single ignition coil so as to create 16 parallel electrical circuits with lower ohms of circuit resistance says more about Sniper’s view of reality than even I previously suspected.
There were 16 separate ignition systems to insure each spark was equivalent.
But the sparks were not anywhere near “optimum” combustion chamber locations, especially spark locations 5 through 16.
Imagine drilling and tapping 16 holes without having a crack run from one close hole to another.
Give the little CFR engine with its variable compression ratio its due respect though.
It was used to discover Octane, Triptane, Tetra-Ethyl Lead and other “Octane Rating Improvement Additives”
At one time these were valuable “Military Advantages.”
MIT PhD student Col Jimmy Dolittle used 130 Octane Rating Triptane aviation fuel during his bomber raid on Tokyo.
Did this student go onto a job with Chrysler/Ford/General Motors/Other where he designed, built, and dyno tested engines?
I do not know but I would not be surprised if he did.
