Aside from shifting, launching can also be a great factor in bringing your time down. My car has and intake and was running 15.2's all night long. Then i membered my peak power and torque is in the 5g range so I feathered or slipped the clutch from 5 grand and ran a 14.9. My trans and clutch hated me but it worked. (Ps that was very embarassing with all these guys here runnin 12's)