I recently put my 2.9 pulley on and my plugs are going in tomorrow, but i was wondering what would happen if i didnt run the plugs colder. The car has been running fine the past few days with the stock ones in. Either way im going to change them but im just curious.

 

The car wouldnt run as great with the colder plugs, it might hesitate a bit after a while.

 

My personal experience is Not needed. I still have stockers in. I have a brand new set from a year ago with 20 miles on them cause the car ran like crap, I regapped them 3 times .32 .35 and .40 and nothing helped. I also was tuning my car at the time so the tune didn't help either. Good luck.

I want to try those spitfire spark plugs once mine our aged a little, but I don't like the fact you can't regap them supposedly

 

I used the zex plugs, which you dont need to gao them, that worked out great, i also treid the bks, which made my car miss after a while, and hesitate.

 

you should run cooler plugs for every 50 HP you add, or if you add more air flow like HP air cleaner etc etc

 

Run the car for a hundred miles and check the plugs if you run cooler ones or just check the stock ones after upgrades and take a look at them also. Might not even need colder plugs even with mods depending on driving habits and such. Make sure they look good and are not fouling cause they are too cold a plug or show any signs they are too hot a plug.

 

Yea looks like im going to change to zex and monitor them after a little bit.

 

wait so, your saying dont get 1 step colder plugs with this setup? (stage2 w/2.9pulley, CAI and gmpp catback?) i have stock plugs right now and was planning on geting 1 step colder after i install my 2.9...

 

1 step colder are recommended for a 2.9 pulley. I was just saying check the plugs afterwards maybe 1 time after a hundred or so miles of driving. I just ordered a 2.85 pulley and will change plugs to 1 step colder but will also check them to make sure they are ok.