Change over to colder spark plug

[GP82]

My motor is currently running 20.5 psi boost pressure with NGK iridium grade 7 plugs. I am soon going to tune for 22 - 25 psi. Is it a good idea to go to grade 8!? (colder plug)

[DevonGT]

Grade 7 should be good enough.

[mikey4410]

best speaking to the "big boys " on these high power turbo setups.

I have heard once or twice its a good idea in your situation. :-D

[DevonGT]

I'm running 23 psi on copper plugs and never had a problem