i have a 4cyl 6thgen accord and was wondering what pipe size i should go with for a cat-back exhaust. (2 and 1/4) is good i thought....i have stock headers and have a short-ram intake byt replacing air filter to a cone k/n filter.

 

2.25 or 2.5 is more than enough.

 

alright thnx man.

Also, i was going to change my stock mufflers to the acura type-s dual mufflers. Any idea how it will sound?

 

On the 4 cyl? It'll probably sound quiet. Why increase the diameter of the piping then use a restrictive oem muffler?

If that's the look you're going for keep the stock piping.

 

am going to weld new tips on the mufflers by replacing the stock and i figured that i would get more air flow when i go with a bigger piping.

 

No real reason to go too big with it, 2.25 at most.