how many miles on the car?

I bet it is your supercharger bearing.

Remove the serpentine belt and start spinning your pulley's. Start with your blower pulley first and go down. The bad pulley is going to make noise since its not spinning smoothly anymore. I replaced my blower pulley a months ago as it was making some horrible noise and didnt want it to lock up. I was going to just swap out the bearing but I opted to put a 65mm pulley on there since I had to take it off anyway. I also did the needwings pulley saver kit at the same time as well.

Mine went mad at about 150k.