Here's part of the info I have in my notes. I don't remember who the original author is though...

"The MAX RPM our SC can spin is 20K but that will distroy it quickly.
MAX safe SC RPM is 15.5K to have any chance of a long life.

Let's calculate SC RPM.

Crank / SC = (Ratio) * Engine RPM = SC RPM

155 / 74 = (2.10) * 5.8K = 12,180 SC RPM (Factory)

178 / 74 = (2.41) * 6K = 14,460 SC RPM

181 / 74 = (2.45) * 6K = 14,700 SC RPM

185 / 74 = (2.50) * 6K = 15,000 SC RPM

Code 3 pulley = 65mm (so I've read)

155 / 65 = (2.38) * 6K = 14,280 SC RPM

178 / 65 = (2.74) * 6K = 16,440 SC RPM

Raise your rev-limiter over 6K when you tune and then re-do the math."

I'm pretty sure anything over 15k RPM is considered maxing out the supercharger. Anything over 16k I'd say you'll burn it up pretty quick from what I've read (the danger zone, if you will).