Ive used Zex spark plugs since Ive been boosted, and I havent had any problems that I know of. A lot of people speak poorly of them, though I havent heard any stories of them causing any harm. Most people sware by NGK's...so I was wondering what NGK spark plugs are the best for turbo applications, one or two step colder, and are they pre-gapped? Thanks!

 

Most people (including me) run 1 step colder for the street.
They do come pre gapped but for a stock non-boosted car.
you want to close the gap up a little. I'm runing my gap at .034 and it seems that most people run between .030- .035 give or take a tad....
Btw if you have an aftermarket ignition you don't need to close the gap as much....thats why i'm runing mine at .034