when I ran my 12.8 I was on 3" bp and stock crank pulley, cooled with inlet/j37, 4"cai and rh/2.75 exhaust, I still don't have bbg installed on my car...I bought it and never put it on, though I launched at 3k ish and according to my datalog never went over 30% throttle in first and didn't go over 75% throttle in 2nd....on 235/40/18 on mugen gp wheels....only took the spare out, but had enough crap rolling around my trunk to counteract that, heard of guys running 12.5 on street tires, but the track was cold, could only net a 2.1 60ft