I have had 17+ years of Hitech with a full 3"/Turbo back,7 inch Canon, with a 4" Resonated tip (5" tips drone). Looks like sex and is still legal volume 84db @ 4000rpm 1M/45deg. If you want quieter the Hitech dual tip classic muffler will suit a fastidious audiophile.

A little Hitech music, Max at Bathurst, March 2016:
https://youtu.be/ykORTBO-qns

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