yeah, I know the difference between running the hotter/colder plugs. I've got an intake and an exhaust, with a race header and ECU reflash planned for the Spring (daily driver). The stock heat rating for the K20Z3 engine for the Denso Iridium plugs (NGK was the other brand I saw) is "22" - they range from 16 to 34 (lowest is hottest, highest is coldest) . If I went FI, then I'd step one colder plug down, according to the turbo kit manufacturer's claims (the place selling it also recommends one step colder plugs for FI, bolt-on stage 1 kits). For every 75-100 horsepower you add to the engine, they suggest going one step colder in the plugs. I've only added about 21 so far, so I'm good with the stock heat range.
I figured I wouldn't need to replace them and I certainly don't want to worry about plugs fouling out. :) Thanks for the advice guys and I'll just stick with what I've got for now in my N/A setup for another...oh...100K miles.
