[Ant]

Mike,

I reckon the 4" looks a bit small, and for the sake of 1/4" closer and 1/4" further out its not an issue, I hate the look of big mufflers, but everyone seems to go 4" which brings me back to the burning issue "is the 4.5" quieter than 4" with the same 3" perforated tube?

I phoned an exhaust outfit today and they said all the bullit style mufflers with 3" internal tube are only 4" OD, I guess the manufacturers only need the 1/2" around the tube for packing, as that quietens more than size to slow the gas flow!

Will look at your gallery to see a 4.5" sidepipe!