Exhaust sizing, changing midpipe

[veovius]

Hi, I've been wondering for a while, is there any downside to going from a, say, 2" pipe, to a 3" for a while, and back down again? Does it make a difference in performance? Sound? I would think that it would slow the exhaust gas down, but I'm not sure. Anybody else have input here?

[S13FX]

There is no harm in it at all, and yes there is performance difference and sound, it all depends on if you go from headers down, or cat down, what kind of muffler your using. Usually when people go big lik 3in it's for thier turbo applications, if your N/A there is no need to go 3in. But a lot of it is only on personal prefrence.

[veovius]

Ok, what about going from say, 2" headerback, to a 3" test pipe, to 2" piping back to the mufflers? So basically, all 2" except for a 3" bulge in the middle?