Should I be switching spark plugs?

[blackdragon0731]

car has 27k miles on it BUT I now have a Cobb Pro-tune and I'm actually getting re-tuned in a few weeks for a boost cut issue that wasn't resolved. Running 21psi peak tapering to 18psi, 50+ whp over stock... should this warrant a step colder plugs?

 

[saxmanbrad]

from everything I have heard, step colder would be good for ya....with the downpipe and fmic, how is your fuel pressure at WOT? I am curious as I am about to install and catted DP and don't really want to have replace the stock pumper..

 

[jsief85]

If you search on the forum "ITV22", which are the one-step colder denso plugs, you will find some useful info. Since you are running AP with increased boost and a catless downpipe you will probably want to run the colder plugs. MSMS3 has posted some really useful info on this in several threads - I was just reading about which plugs to use yesterday. I believe that with the AP you also need to decrease the gap in the plug to 0.026". There is also quite a bit of info on this from Cobb and others on here about this decreased gap being optimal for a setup like yours.

 

[blackdragon0731]

Well I didn't run into any problems with my fuel pump during my tune in september, so idk it varies car to car. I'll do some more searching especially about the smaller gap running the AP.