As Chip says, anything can happen. The billet front drums do not prevent the sprag from failing which is the reason the drum is spun up so fast in the first place. Along with the front drum, the sun shelll is also being rotated at 2.2 times engine speed. If the billet drum has a small flaw or the sun shell had a crack or a slight imbalance condition, either could explode after a sprag failure. The TCS testing shows their aluminum drum failing at a little over 22K which translates into an engine speed of 10K. Not that unrealistic if you have a sprag failure at launch when your right foot is planted on the floor. Sure, there's rev limiters, but there's always a chance that something may fail. Better safe than missing body parts!!!