I've got a similar noise turning right under acceleration. The Service tech says "wheelspin" I say B.S. if so why do the tires squeal when turning left and front end thunk when turning right??? I am going to take a good look this weekend It sounds like something loose. Possibly motor mount? It sometimes does it from a stop going straight with hard acceleration, also from a hard turn with med. to light acceleration. The harder and faster the turn (the more the passenger side is unloaded) the more likely the noise.
I think I hear it when going over bumps, but that could be my imagination.