I'm going to be doing a custom exhaust on my celica pretty soon. Some say go with 2.25-2.5 straight pipe exhaust and some say cat back. Is there any performance difference between the 2? Keep in mind i'm planning on turboing the 5sfe next summer.

This post has been edited by hs2g: Oct 2, 2004 - 4:12 PM

yeah there is going to be a performance difference well cuz the less bends in the exhaust the better it flows...of course the straight pipe would gain more hp then the cat back but would sound hell of alot louder...but the cat back is nicer....cat back is the way to go ...just get headers and exhaust cat back system and it will purr nice and still gain hp....plus the hp difference isnt going to be that big there is only soo much that you gain...

or just run open header hahah thats the best...until the nice cold are gets in

If your gonna turbo in less than a year, just save your money and wait, or get a 3 inch and live with the power loss for a while. I dont think you'd want to buy 2 exhaust systems within a year.

but is 2.5 good enough for turbo? I see some people say 2.5 -3 inch would be fine.

2.5" is all you need turbo or nonturbo any bigger than 2.5" on any celica is not worth it and not produce that better power either

So your saying with a 2.5 inch pipe I can gain same HP and torque? I'm guessing maybe in a range of 8HP.

Exhaust systems on n/a lower compression 4 cylinders don't make that much power...