how much should i retard my timing i am going to run about 6 to 7 psi on a d15 with 450cc and afc hack and can i retard it with a adjustable time gear?

 

are u refering to the timing on the cam gear? try 2 degrees retarded, seems good on my butt dyno but the best place to tune it is on a real dyno. every setup is diferent. if your talking about ignition timing leave it stock first. tune it the best u can before u mess with that timing.