slip on muffler diameters

[TheSouthsider]

Hey all, gonna replace my slip on mufflers with some new ones,and just wondering the effects the size diameters of the mufflers have on sound/engine breathing/etc. My present ones are 3 1/2 that oval out to 4. Thanks

[hd02us]

I think the baffle size has more to do with sound than the muffler diameter.

[Goose912]

There are many factors that affect sound. Diameter, wall thickness, construction of the baffle, etc.