like most of you, i've been running irridium 7s in a stock jdm itr engine on a p73 ecu. usual black soot and kind of gassy smell happens from time to time. by the way, this is not at all slimey oil burner black. it's rich powder black.

been tinkering with the motor more since it's getting turbo'd really soon. just happen to have a flash back to my rich *** lawn mower and what happened when i put a hotter plug in it, basically cured the problem.

just for fun i bought some $2 copper 6s and bolted them in.

driven 100 miles no

no black soot, no gas smell, no black puff at WOT

this post is what it is, just a test, thought i'd share