Dynomax Super Turbo's on my Superbird are as good as I would want,not much difference than the original Street Hemi muffler.On my 62 wagon with full 3" Max Wedge exhaust,it is a different story,much louder than I like.From what I have researched,in 3" at least,the Super Turbo's are still the quietest muffler available and still one of the best flowing.