"Well if you cannot be fast you might as well be loud."
Heh, this is what I tell myself while riding my Suzuki DR 650RS. She sure is loud and slow compared to the beast. I had to put the db-killer back in the silencer since otherwise she made children cry bypassing them on the streets. Friend of mine on his Harley said he had to leave like a 100 meters distance behind me ´cause of the terrible noise. He could not hear his own bike anymore.
Back to the Rocket world; I believe the TORs are loud enough. The only modification I have been thinking of is to replace the collector box with a better flowing one. I do not think it makes the beast too loud. The only thing is the cost; 350€ for a piece of pipe is alot if you ask me.