2.5 vs 3 inch exhaust,
 

I have a greddy turbo an manifold. I am thinking about redoing my exhaust without a cat and resonator.

My goal is 200hp or 9 psi, which ever comes first.

What are the pros and cons in these two different exhausts sizes?

Nick

Re:2.5 vs 3 inch exhaust,
 

Choose whichever size is approximatly 10% larger than the turbine outlet diameter. Bigger is usually better but not in every case. For your power goals, a 2.5" will be more than suffecient. If you plan on a power increase later on, go with something larger. Just make sure that you compensate for drag in the muffler, cat and/or resonator by a suitable diameter increase.

Re:2.5 vs 3 inch exhaust,
 

member best exhaust for a turbo is no exhaust.

ive seen some guys go from a 3" exhaust to just a downpipe. and they gained 100hp no ----!

if u can do 3" for sure go for it. hell do 4 ;D

Re:2.5 vs 3 inch exhaust,
 

open downpipe is best. I read a good writeup on this once. Check the Faq at turbod16.com for more info from one that designs turbo systems.

Re:2.5 vs 3 inch exhaust,
 

either exhaust will get you your goal.. 2.5 fits nicer under most hondas.. but if you can afford 3, and you can find a place that will do it.. Go for it

Re:2.5 vs 3 inch exhaust,
 

a 2.5 system should be more then big enough to flow 200hp worht of air. ive made 225WHP with a 2.5 inch mandrel system. just dont get crush bent pipping.

Re:2.5 vs 3 inch exhaust,
 

I was just wondering if anyone of you guys use your stock exhaust or did most of you upgraded to 2 1/2?

I hate the sound of a huge exhaust and would much rather stay stock exhaust.... but just wanted to know your thoughts...

(sorry for hi jacking ur thread... just didnt want to start a new one for this question regarding exhaust)

Re:2.5 vs 3 inch exhaust,
 

I used stock exhaust...it sucked donkey dick :P .
I ran open 2" downpipe an it was sweet...connected it to my stock exhaust system that was like 1.5" or somthing ...like a straw and the turbo spooled soo late man and it died at 6500 rpm that was just sad....I just could have left the car NA :(

Re:2.5 vs 3 inch exhaust,
 

Huge exhaust w/ out a turbo sounds like dogshit, huge exhaust with a turbo actually sounds pretty decent, a turbo is a muffler ;)
I'd say a good 25-35% it quiets it down.

Jeff

Re:2.5 vs 3 inch exhaust,
 

I second that...I had 3" on my can when I was N/A and it was annoying as hell, After I boosted, it really sounds nice. (Full 3", no cat, dynaflow muffler)