My limited experience on engine dynos has not been good.Seems that the dyno has a hard time simulating load because when I put the motor in the car I had to re-tune.I have installed a wideband o2 in my car to help me along and has been a big help.Its another tool in the tool box,i don't live and die by it.When at the dragstrip it seemed that the fatter I made it the faster it ran so that's my dyno.