I run a two inch twin with three inch tips. It only runs hot dogs but the balance bar keeps it quiet around town and it doesn't crackle. It certainly wakes the neighbours if you give it stick. Not everyone's cup of tea, but I like loud. I used to run straight throughs on the same system, with no resonators and it was polite enough to not be noticed, but had the desired note under the right foot.
If you get too big, with no back pressure, you'll start damaging valves.