I'm redoing the exhaust on my friend's prelude because the current set-up is unacceptable and awful. It consits of the following:
1-Missing Bolts that connect the pipe right after the headers causing the exahust to hang too low and scrape.
2-Universal Cat
3-2.5in piping, no resonator
4-Cheap universal muffler

Here is what I propse to fix:
1-Get replacement bolts for that pipe so that it hangs at the correct height.
2-Leave the cat
3-2in or 2.3/4in piping after cat
4-Apex-i Universal N1 Muffler with optional silencer (For his mom)

Now, my problem is whether I should go 2in or 2.3/4, please advise on which is the better size to retain proper amount of back preassure but still gain HP. Plus my friend wants a really loud exhaust which is why I chose the Apex-i unit. Thanks in advance.