Done the wired george coil mod on my z thou tonight. It's such a cheap, good but simple mod, has made a helluva difference .. Basically it's this..
I've just changed my coils for high voltage jobbies, but still didn't have that nice, big, fat blue spark you want at the plug. Apparently, older wiring gets a bit faulty, builds up resistance etc, so your not getting the full 12v to your coils.checked mine and sure enough, 12.7v at the battery, and only 10.8 at the coils.
So all you do is wire in a relay( I did two, one for each side) so that the 12v permanent feed wire to the coil is now the trigger wire to the relay for a switched direct connection to the battery. And that's it..12.7v at the coils now too.
2 volts on the low tension circuit isn't much, but probably gives a few thousand more on the high tension side...it's certainly given me that nice fat spark I wanted :-)