Celica Forums General Discussion Engine and Performance Exhaust Size VS Muffler Inlet Size

When looking at an exhaust for the celica, (e.g. axel back like the TRD), only the diameter of the exhaust piping really matters right?

I think the TRD is 2.5", but what about the muffler inlet? Would that be 2.5" as well?

Reason is because i might be getting a custom exhaust, so i will be looking to get 2.25" piping from the cat into a muffler like n1 or something. So i'm asking does the inlet of the muffler matter? I found a muffler that is 3", it is supposed to be for a turbo, but will it work?

I'm thinking the muffler size isn't really relevant, it's just that with a 2.5 inlet you can easily connect it to a 2.5" exhaust piping without mods. am i correct?

get a 2.5 inlet so it will be easier to install. i got mine frome ebay
for about 40 bucks shipped. it works just as good as a 100 dollar muffler.