I need help. I've looked and never really found a definite answer, what spark plugs should I run? Engine is a 4agze turbo. I put the oem recommended plugs which are rated as 6's in and it misfired when it started boosting. I would take a lap drifting and it would be fine then it would misfire after that. The car runs 15psi of boost. Was told I need colder rated plugs (7's or 8's) . I read that some 4ag guys use bkr7e's, but I am not really sure if that is what is right for my case..

The stock plugs should be fine but you can pull them and read them.http://www.ngksparkplugs.com/tech_suppo ... p?mode=nml

What is your gap? Try closing the gap a couple thou.