Need input on exhaust setup

[rpeatt]

Ok you guys get this all the time, and i rarely frequent the exhaust forum because i have no clue whats going on. But..... I am finally upgrading the exhaust on my car. Now, I want to go 3 inch, but I dont have a 2.5 inch swingvalve, although I do have a 2.5inch downpipe waiting to go on. I can't afford the sv for the 3" dp. I also hear that it is a pain to install 3" in G Bodies around the gas tank. So:

Do I buy the 3 inch cat back system from FWD and use the 2.5 dp, no cat, with a dynomax ultraflow muffler

OR

Do I buy the 2.5 inch cat back system from FWD and use the 2.5 dp, no cat, with a dynomax ultraflow muffler

Mods are as follow:
-Ported/Polished Intake (with 52mm tb), Ported/Polished Head (with 3 angle & backcut valves), and Ported/Polished Exhuast manifold
-Talon 1G BOV
-Relentless stage III Cal at 15 psi

I'd think a 2.5" would be enough. Talking to people, it seems like a 2.5" would be enough for the 18 psi I will be running, though I've been recommended to get a 3" system. I do have the 2.5" swingvalve, however. I just don't want any boost creep.....

[rpeatt]

ttt

[Garret]

If you wanna beat Ian you'll need that 3 inch but seriously might as well pony up the extra 30 bones or so and get 3 inch

[guyd_15]

Do it right. 3" swing valve, 3" downpipe and 3" mandrel for the rest. No cat or muffler. That's what I did and the cars not to loud.
Spools quicker.
Guy

[scott_s]

If your down pipe will be 2.5 I would stay with that all the way. However, if you plan to upgrade the dp and sv later to 3" I would go with your first choice.

I put 3" sv and 3" exhaust with a hooker muffler and I am really happy with it. Freed up enough restriction my boost went from 12 to 17-18 (not creep)

[2Lebarons]

Quote:

Originally posted by guyd_15 Do it right. 3" swing valve, 3" downpipe and 3" mandrel for the rest. No cat or muffler. That's what I did and the cars not to loud. Spools quicker. Guy

LOL! whats your idea of not too loud? your ears arent bleeding, so its not too loud? i have the 3" pipes on my 89 lebaron now, no cat, 3" dynomax turbo muffer (which is really 2.5" core)...yeah, thats right..i said turbo muffler, and i think its too loud for my tastes. i couldnt imagine it with no muffler, or one of those useless bullet mufflers on it!
i just dont buy into that nonsense about turbo mufflers killing performance on turbo cars....