I have been using Ngk copper plugs on my race car forever. One day before a race I ran out of them ( I swap out plugs for fun since they are so cheap). I looked at the Iridium plugs I have instock and was kind of iffy on using them. I had no choice so I did. That day at full 23psi and 505HP ran at least six times at the track without a single problem so I been using them ever since. I still have the same set in my car till today since they are quite expensive from Greddy. ( Greddy contracts with NGK)

 

do you happen to know your AF right off hand?

 

Me? yea...FJO wideband sensor unit.

 

I differ with Guru on this one (we generally agree ) only in that platinum is a horrible conductor of electricity....I have found just oo many misfires on high hp setups we have done before using platinum plugs (either NA or turbo setups). YMMV

 

What should I gap my iridium 1 step coder plugs while running a 9psi ATI setup. Thanks

 

Recommended gap is 0.030 to 0.040 (I went 0.035). Narrower gap is to prevent spark from blowing out under boost. When gapping Iridiums, you've got to be extremely careful not to break off the brittle central electrode-- a needle-like wire. I use needle nose pliers to grab the negative at the 90 degree bend. Just touching the electrode will snap it. Also, if using a feeler gauge, just slightly jamming it will snap the electrode off. You're almost better off leaving the gap where it is--about 0.04 from the factory.

 

Does anyone have a part number for a good copper 2 steps colder?

 

I have a set of 2 step colder NGKs that I am taking off my car. I bought the 1 step. Ill give you the 6 for 40 shipped. Cost me 12 a piece. 6k miles

 

Thanks, but for the amount that they cost, I rather just buy new ones.