Originally Posted by modme

Here you go: HKS USA M-Series Super Fire Racing Spark Plugs

Thanks, I appreciate it.. What heat range did you go with? Is 8 one step colder from stock or its the stock range? Is 9 two steps colder from stock?

been running these since day 1 with twin turbos.

Originally Posted by Dembflyr

Got mine from GTM. I'll have to check the part number when I get home later in the week.

Originally Posted by wstar

The ideal you're shooting for is "just cold enough to not cause any dangerous knocking" + "hot enough to keep itself clean so it doesn't foul quickly and misfire". It's a delicate balance, and going colder when you don't need to can be detrimental in the long run if those colder plugs build up carbon fouling.