In some prior drives I had been hearing a lot of chirping when the superharger would engage at ~1500rpm . So I removed one shim from the pulley. A week prior to it spliting in half leaving only the stock pulley installed ​from the factory ; less chirps. Visually checked everything during my lunch break and the gap had grew back to where it was prior removing the shim... This may have been when it split. Pulling into the garage i could hear a shuffling noise then I made the discovery.