Exhaust piping

I want to install an exhaust on my car, but I really don't know how big in diameter the pipe from the cat-back to the muffler should be? 2 1/4 or 2 1/2. The car is a honda accord 2.2 L engine. Thanx:sun:

Are you going to install a turbo or a supercharger?

I'm going to install a turbo. Some people said 2 1/2 was better for turbo. What do you think?

IMHO, 2.5" would work best.

Whatever size pipe you're going to have from the turbo to the cat is what you should have from the cat on. 2.5" would probably be best for you. If you can get 3" to fit your car (and your budget), it would be the performance choice, but you sacrifice a little driveability. BTW, make sure you get mandel-bent piping. Crush-bent piping will do you no good with the turbo.

Adding to that - don't neglect the downpipe (is that what it's called? From header[s] to cat[s]).