ORIGINAL: nitro fanatic
you should be hearing just a crisp clean rev just play it by ear if its not overheating it shouldnt be overreving
Exsalty... If you don't know how it should sound then just watch the temps and even more importantly make sure there is a thin trail of blue/gray some coming out of the stinger.
You can rev the engine when there is no load... But don't do this for long periods of time.