I would like to know which spark plugs to use for my setup. I am planning on making 650whp on C16. I am using s300 and stock ignition with a Msd SS coil. I have searched for the last three hours and I am still undecided. My tuner recommend heat range 8 or 9. Any help? Thanks.

 

go with ngk 9s

 

Well I think I am going to go with NGK BKR8EIX or BKR9EIX. I might get some BKR7ES-11 for the pump tune and street driving. I am going to gap them down. These are resistor style so I should be good.

 

Buy a set of each and let your tuner decide. They should be the one telling you what plugs you need 99% of the time.

 

Oh, he did tell me which ones to get which were the Iridium's I posted above. I just like to check around and see what other people think.