What is the reasoning behind no platinum plugs with SC?

[ColdScrip]

I know that there is some issue as many people have posted to not use platinum plugs with supercharged cars, but why?

[Cooey]

I think it's because the platinum plugs cannot handle the heat like copper or iridium; when I did my first plug change [after joining this club] I noticed the old platinum plugs electrodes were worn down considerably more than I have ever seen plugs "wear".

Put in NGK iridium and no issues.

[93RedSled-SSE]

Never mind...

[Bonneville92V688]

The small platinum electrode in the plugs cannot handle the boost, heat, and occasional pinging that happens in supercharged or turbo'ed situations. They easily get jolted and break out. I mean yeah... if you really want the platinum plugs, put them in, but I guarantee you would be changing them out every other week

Also goes for NA engines. We put Bosch Platinum plugs in my Dad's 4.7 Durango, and it was misfiring, and hard to start 2 months after we put them in. 6 of the 8 plugs had the platinum electrode missing. We put the recommended Champion copper core plugs in, and no problems since.

[willwren]

Yes, the plugs fire twice per cycle, one for ignition and one a waste spark. This is more of a problem in the SC engines too.

Platinum are fine in a NA application. Just not BOSCH platinums, as they don't survive in a waste-spark system.

The reason for no platinum in a forced induction (SSEi) application has nothing to do with the waste-spark issue, and everything to do with heat dissipation in the electrode.