Exhaust size?

[CrawlingEye]

Well, I was thinking of doing my exhaust within the next year, so I figured it would be a good question to ask: What diameter exhaust should I get?
I'm thinking of doing the muffler/tip shortly and then getting a new header, and eventually maybe a high-flow cat converter.

What size should I get for the muffler/tip?
I was thinking of going borla with it.

I really like the look of the square intercooled tip:


but I don't know what size I'd need. I know it'd be determined by my muffler, likely, but I'm lost on that one.

Also, what muffler would you guys suggest? I don't need something extremely loud, but some mild rumble would be cool.

Thanks in advance.

[Warped]

2.25" for the i4 is the norm. I've heard the Apex'i WorldSport is pretty quiet...

[CrawlingEye]

Originally posted by Warped
2.25" for the i4 is the norm. I've heard the Apex'i WorldSport is pretty quiet...

Thanks a lot.
I forgot one thing. Does it matter if I get a straight muffler, or should it be one of the ones that goes in the center and comes out offset, or vice versa?

I was thinking straight would probably yield the best performance, but I'm unsure of how well that would actually fit (if there's any difference in fits)