Ok, I know this may have been beaten to death. But i gotta get it right. I have meth running stock turbo evo 8 pushing around 385whp. I have been running BR8ES spark plugs. Honest have to say these spark plugs only last 1 oil change from my experience and kinda annoying. Im want to try iridium plugs.
My questions : Are iridium just as good as copper in performance but last longer?
Is NGK BPR8EIX the right step colder for my performance?
NGK or Denso?
Iridium: does it need gapping?
Or should I just stick with copper and live with it.
I would just close up the gap some to like .023 and make sure the grounding strap is parallel to the center electrode surface. When you bend the ground electrode over to close the gap it tends to make it an uneven surface that wears faster and opens the gap.
Copper is fine, but there is nothing wrong with the stock Iridiums. I was using my stock plugs with 38,000 miles on them, running 30psi on stock turbo with E-85. I just recently starting to get some misfiring. I replaced the plugs with another set of stock Iridiums and all is well again...boosting 30 psi on E85.
Again, a matter of choice. Pay less for the copper, but change more often. Pay more for the Iridium, but change less often.