actually, sorry, but you can have them on internally gated turbos makes no real difference really, probably just easier with the external gate.
And, they are obscenely loud, aren't they Jeff?
Anyway, just get propper dump/front pipe made with the wastegate pipe coming in after a certain length, there is a thread on this somewhere, quieter and keeps the EPA off your ass (hefty fines too, i think $15000 if you are caught, not 100% certain on this though).