Plug Gap With MSDs

[Disturbance]

So I'm gonna be running autolite iridium plugs with MSD 8.5 wires. The guy at auto zone told me to gap at .035, the book tells me between .026 and .032 and everything I have read on here says to gap at .028. So with my setup what gap should I be running?

 

[NHerron]

I wanna know why you're using iridium plugs and not NGK coppers. Maybe MSD makes iridium worth it for whatever reason but iridium usually is worthless unless they go in a car where the spark plugs are a major PITA to get at, therefore extending service intervals is a big deal and thats where iridium comes in.

 

[sidewaystsi]

Go with what the service manual says if your relatively stock.

 

[Disturbance]

Thats just what i have used in every one of my cars for years and never had a problem. Plus its an upgraded plug from normal copper.

 

[NHerron]

Upgrade to service interval I guess. Not very difficult to change plugs on our cars though..

Copper is by far a better conductor, in a boosted application I'd take performance over the benefit of changing 4 plugs at 40k-50k instead of coppers 20k.

 

[Disturbance]

Well i was under the impression that iridium performed better, but after some research it looks like the coppers do. I guess i will be taking these back and getting some coppers

 

[Diamond Star Werks]

Well i was under the impression that iridium performed better, but after some research it looks like the coppers do. I guess i will be taking these back and getting some coppers

It does perform better. Mine work perfect up to 18-19 psi 30+lbs/min

Get ngk or denso not autolite.

 

[NHerron]

Here OP, this is some other cool info
http://www.dsmtuners.com/forums/frequently-answered-dsm-questions/233421-spark-plug-faq.html

It does perform better. Mine work perfect up to 18-19 psi 30+lbs/min

What performs better?