i'm soon to be running ~7 psi w/ hahn kit. right now i have stock heat ngk iridiums. anybody had issues with them in a boosted application?

I got NGK TR6IX in my 2.4l and I can't complain.

I am running NGK BKR6EIX iridiums 0.40 gap at 12 psi. in my Cobalt SS supercharged. You should be ok with that hot of a plug with 91 to 93 octane. gap would be best no higher than .45 no lower than .40

What about the AC Delco 41-101 (the plug in the 3.8 SC)?

You guys should know better than to use irridum plugs with boost, these are a very bad idea because they are such a fine tip that they can glow and preignite your fuel charge on the compression stroke and cause spark plugs to fall into you engine at 250 KM/h I know its happened to me, it destroyed my block and cylinder head but did not break my weisco pistons which held up. The best you can use is copper, its cheap, reliable and it bleeds heat away fast, I am using RS12yc in my 2200 and they work fine.

Jonathan

Quote:

You guys should know better than to use irridum plugs with boost,

Depends on the timing and the heat range. Boost is only dangerous if you plan on using platinum. There are about a hundred people on Cobaltss.net running iridium plugs at 17 psi with no problems whatsoever.

I have worked with several boosted cars which specifically use iridium plugs to help offset the overly rich condition encountered with larger injectors and no way to tune properly. I'm currently using the 41-101 in my turbo'ed 2.2 and have had no problems since installed, maybe a year or more ago?

As menstioned above, timing and heat range make all the difference.

-->Slow