You can get louder whining out of the Turbo without having to do anything to it by deleting your muffler, the foil on the turbo to intercooler tube, and/or putting on a Tymar/6637/BHAF type air filter set up. OR, you could purchase and install a "Wicked wheel", which requires partial disassembling of the turbo and careful installation procedures. OR, you could get an aftermarket turbo. OR, you could put on an aftermarket ported housing with your stock wheel OR a WW. HeBLEEPll theres LOTS of things you can do in combination or alone to get louder whistle out of a 7.3s turbo.
Know what you CANT do tho? You cant do anything about the silencer ring on a 7.3 turbo.
know why? Cause there isnt one.