I'm running a VF30 right now on my car with higher boost. I was thinking about running some HKS or Denso Iridium spark plugs that are 2 steps colder than stock heat range. What are your opinions on these Iridium plugs.

I've got the denso plugs in my car, I'm not real highly tuned and have no idea if they've helped or not, but I sure as hell haven't had any problems. And from what I've seen they seem to be the best quality w/ the most backing them up as far as being from japan for japanese cars. just my 2 cents

i have the ik20's i think. the ones that are one step colder. before i was throwiing cels for misfires and the dealer could not fix it. (but they knew the codes) they said they couldnt replicate the problem. anyways i decided to change the plugs myself and so far so good. this was a year ago. but im not hightly modded either. denso's are quite good.

I had the same, Denso, no problems. Also, I was running a VF30 and sti injectors.

Pete

I had Denso IK22s on my car....erradicated and detonation at the time...but they are race plugs and need to be swapped more often then normal plugs, and at $12 a plug that is not cheap!
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