I've just got off the phone with an owner of the local performance shop. My car has a drivability issue. It loaded up from idle to about 2k (part throttle). When I gun my car, it hesitate for a couple of second then the monster came out. I call him to see if I can get my car tune to get rid lf the problem. He thinks it could be mechanical issue. This engine has less than 20k (5.1stroker sith Paxton s/c 16.5 psi). What do you think tuning problem or mechanical, thanks.