Exhaust...2.25 or 2.5in and over or under axle??? Options

[Davesceli]

Which is better for a stock 5sfe, 2.25 or 2.5in pipe? I've searched around and its a pretty even split on opinions between them. I've decided on the HKS Carbon TI muffler with the 60mm (just over 2.25 in) inlet, i know its expensive for a stock motor but it looks damn good and sounds sweet, my mind is made up. Carbon fiber is just so sweet!!!!

Now i just gotta decide what size piping, its gonna be catback, and whether or not to go under axle or over. What are the pros and cons of each??? If i go "under axle" will there be any clearance issues since my car is lowered???

i know this question comes up a few times, but im looking for a definative answer...i've searched alot and i still can't come up with a good answer.

[95CelicaRacer]

If you plan on keeping the 5sfe stock, I would not even have a bigger pipe size. Any size that you go up will cause you to lose torque, and if you have those crush bends in the pipe, you will build up turbulence in your exhaust flow. You can eliminate the secondary converter if you want to. That alone will give you a better tune coming out becuase of the less restricting air flow, and you may gain 2-4 Hp.