what will the limits be of this setup? i have a 2.5in dp, and i was thinking of either a 3in exhaust or a 2.5in exhaust. how would a 3in exhaust benifit me if i have a 2.5 downpipe? am i not limited to the 2.5in exhaust and what that will flow? how will 3in be more free flowing if the smallest area is only 2.5in?

i'm running 16psi on a t3/t4b on my stock F23 and i definitely can feel a restriction when i'm at full boost and in the upper rpms, before i do my exhaust, i'd like to know what u guys think. anything will be better then my current exhaust setup.............2.5in dp->stock gutted cat->2.25in cat-back, 16psi is going through this, its a shame, but hey, it still pulls hard:D
i dont think i want a 3in downpipe, think i'd like to stay with the 2.5 downpipe since it's already their. but i do like to know how much will the 2.5 downpipe be able to make, will i beable to max out my t3/t4b on a full 2.5in downpipe and make pretty good numbers?

how will a 3in exhaust bolted up to my 2.5in downpipe benifit me over a 2.5in exhaust? should i go with the 2.5in or 3in? and 3in downpipe is not a option here, sorry.


i'm really interested to feel the difference from my current setup to a 3in or full 2.5in exhaust, especially since i'm running 16psi.

 

bump, would also like to know about the 2.5" dp with 3" exhaust

 

i know theres more of us then that running a 2.5 downpipe

^^^bump^^^

 

Bigger is ALWAYS better. It gives exhaust gases more room to expand and creates a better pressure differential for the turbine.

 

Hey. This is my first post, but I am hoping that I might be a LITTLE help. I don't have a moded honda/acura yet, but am looking into it as they are cheaper then what I have currently.

Anyway, here is what I have gotten from more technical posts. The BIGGEST restriction in the exaust portion of a forced induction is the downpipe. I have a WRX (I know...get the hell out of our forum), and that is the part of the exaust that causes the biggest issues in performance. Your biggest performance boosts would be from a larger downpipe if you can get one to fit. I am also assuming that you have all of your cats pulled. If you dont, getting either a high flow (so that you dont get a $10k ticket), or pulling your cats (for those that dont think they will be caught).

With my current setup, I am running about 260hp/265lb torque and I am not close to needing 3" pipes. 2.5" is plenty till you start pushing 350+ You would be better off spending the money on something else if you are not close to that. RyanCivic2000 is right though in that bigger is better. If the rest of your exaust is not 2.5 yet, and you are going to buy one or the other, go with 3". That way you dont have to upgrade it later if you are aiming for higher then you have now.

Lost a bunch of what I said in an editing accident. Hopefully it all still makes sense.