I just got a 00 turbocharged S2000 and it desperately needs plugs. I went ahead and put NGK IFR7G-11KS. After that, I did all the research I could and found people saying Iridium plugs are BAD for turbo cars, also I need help with the "heat range" because some say one colder (8) and some 2 (9). I also have some almost new Denso IK-24 plugs I can put in there. Are either of these plugs okay or do I need yet another set of plugs? My car made 414 whp running right, which is breaking up under boost now.

 

You would be better off asking this in the fi forums. You definitely want the colder plugs. I would switch to the denzo ik24 or Ngk bkr8eix

 

Typically, one heat range colder is enough unless your running alot of boost or don't have a intercooler or some other condition that will increase the chance of preignition. I'm not sure that an iridium plug is bad for a boosted motor, its just that some people don't use them because you change plugs more often when boosted. One of the main purposes of iridium plugs is longevity so your not getting your moneys worth if you change them frequently. A smaller gap may help out with the breaking up under boost.

 

I did gap them at 25 and the other plugs I have are the IK24's so its sounds like those would be better.

 

https://www.s2ki.com/forums/index.php?showtopic=843022

 

Search, you'll find enough info on plugs to make your eyes bleed.

 

That is so true!!!! haha.

IK24's would work good. I ran those in my Subaru years ago with about the same power as you are at.

I would stick with a 8 heat range plug.

If you have a set of IK24's, I would just run those honestly. They are good plugs.

 

IK-24's it is then

 

Besides the low cost, I always thought copper plugs were used because they produce a better spark (than iridium, or platinum) assuming they are in the prime of their lifespan. Any truth to this?

 

Iridium is fine, I would recomend a set of BKR8EIX gaped at 0.027"