over at moparchat there is alot about it. this is the little bit i know about it. the drum spins at 2 1/2 times the engine rpm's which they are capable of handling untill the sprag fails and the rpm gets out of hand. yes there are tests on it. anything that unloads the sprag fast will hurt it. like a broken driveshaft or ujoints, axles, ring and pinion etc. a burnout in first gear where the sprag freewheels then stops when you hit the dry pavemant. short shifting at 7000rpm's is impressive to me.