I've been searching to find the theory behind cold plugs making more power?

I read [wikipedia, O.S. guide] all I got out of them is cold plugs make more power.

http://en.wikipedia.org/wiki/Glow_pl...odel_engine%29

http://www.osengines.com/accys/choosing-glowplugs.html

Here is my theory - but it is just a theory. Colder plug=slower combustion = lower engine temp = you can run it leaner.

Colder plugs do cool down more betwen the combustions. With the next combustion the plug is colder so to create an ignition the compresion needs to be a bit higher. With other words: a colder plug shifts the ignition to a later moment.

With a shifted ignition you will get more rpm but if you correct the ignition back by lowering the button head you will get more compression giving more power.

I'm racing this weekend and I going to try a cold plug during one of my qualifiers. I'm currently use a medium plug with 30% fuel.