stock sedan muffler/pipe size

[Vervepipes]

I may be getting into a deal to try a more silent performance muffler that would be built to suit my car, but I cant find using the search the stock dimentions of the muffler and pipes. Supposedly it produces the poswer of a straight pipe but retains near stock Db levels. I remembered about the thread on a CRX forum and went back to see how it's doing, and they're negotiating on a price.