how Spark plugs work?
Very Simple Ignition coils/plug wires make them ignite with air fuel in the combustion chamber.
And more simpler thing is Iridium Spark plug produces more spark then Copper 1.So more spark means better combustion of fuel hence efficent combustion.
Yet plugs should be chosed as per the motors requirement specially incase of aftermkt setup. So for the same reason I dont agree wth the very first post of Mr. Spoon as it not mentioned which plugs have been used.2ndly materials do change their properties whn they r put in certain conditions so dyno should have been performed after some runnin.
The role of ignition coils/plug wire is to supply charge to Sparkplug to make it ignite.Less resistance means more charges delivered n better glow of plugs.