spark plug gaps and temperature on boosted motors

[Spiller1327]

So I've been researching about running a one step colder plug in the Rex when I go stage 3. And a friend mentioned possibly a bit smaller gap for proper ignition while running more boost. Who has more knowledge on this?

 

[drvsdwz]

just go with the one step colder. the ngk's are already gapped, as well as the denso's which are both iridium, so no need to gap. haven't had issues with engine knock either

 

[RyanR]

Simple way: One step colder iridiums, check your new plugs and set them to the stock gap. I've seen even the iridiums come improperly gapped. When you tune, your tuner should notice misfires/power go flat when the boost comes on. Close the gap .002 and try again if that's an issue.

More adventurous: The bigger the gap, the better the combustion, so I'd start at .031 and work to .028 if necessary. Make sure all plugs are equal.