I just got some iridium spark plugs for my car. I need to retard my timing, because im going to be pushing 8 psi or less on a t3 on my b18a. How much should I retard the timing? Someone told me around 1 degree for every 2 psi, does this sound right? And would it be ok to attempt this without a timing gun? If so how far should I turn it? I belive I turn it away from the front windsheid.