When we first started diagnosing the belt issue we ran our Magnum race car on the dyno and shot video of the belt. If you use the link, you’ll see how violently the belt S-whips on the 1-2 and 2-3 shift. See “Belt issues on blown late model HEMI”

Of course, when you make a lot of power, it’s not just the belt under stress. The factory tensioner itself is a very lightweight and thin cast aluminum part with a plastic pulley. Between belt whip and tensioner flex, carnage can result. Let’s look at some of our own past experience with carnage.

Some remains of the five belts we shredded during a single dyno session in 2016.

The violent back and forth whipping action of our 900+ HP car on the track snapped the locating lug right off of this OEM type tensioner.

Carnage isn’t limited to belts and tensioners. When the belt broke on this pass it managed break off two of the ribs on the power steering pump.