???

Anyone? ?

Would the car knock due to using stock heat range vs colder plugs?

I was wondering the same thing about changing plugs..Maybe the colder plugs cause less knocking or your other plugs were bad and the new ones were firing better making more power can cause it to knock a bit more.

What fuel are you running and what psi?

I'm currently running bpr8es (coppers) on the setup in my sig, works fine. They seem to need replaced every 8-10k miles, but they're only $10 for a set, so its not a big deal..

I ran denso Ikh 24 and they worked ok on WOT, but would foul easily on idle, and when cold, sometimes making the engine impossible to start..

I've always ran bpr8eix plugs with no issues.

we run BPR7eix in EVERYTHING evo 8, OEM plugs in evo IX/X

Agreed ... especially where the use of E85 is concerned.

Good to know thanks for the input, I picked up some bpr8es gapped to .020 running E85 gonna be pushing 30+psi mark see how they hold up.

Good point, E85 should burn much cooler, so less need for colder plugs.

I think BPR/BR 8EIX should be ok for most pump gas applications.