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Discussion Starter · #1 ·
opinions? not sure whether to go with 2.5" or a 3" from the o2 back?
 

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2.5 from the 02 back with no cat is just too loud. Believe me i've done it. Your best bet is 2.5 with a 2.5 cat. if you are running stock then this is more than enough
 

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When i had the T-bird with Zebel o2 housing it was 2.5" with test pipe wasent that loud
 

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2.5 from the 02 back with no cat is just too loud. Believe me i've done it. Your best bet is 2.5 with a 2.5 cat. if you are running stock then this is more than enough
HA, you should hear mine with open dump :p
 

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Discussion Starter · #9 ·
well the only upgrade to the turbo i plan on doing is a tbird. i have the 2.5" zebel housing which i will use. just wasnt sure if there was any more advantage really to 3" over a 2.5" or if there were any bad side effects of a to large of an exhaust on a small turbo
 

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Mine starts off as a 2.5 inch downpipe and the goes into a full 3 inch system from there and it does sound good not too loud at all but sounds deep. I would'nt worry about what kind of turbo you have on, I believe when it comes to exhaust the bigger the better.
 

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the bigger the better is not such a good idea. you will lose some low end power running an exhaust that is too big simply because you have very little back pressure
 

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the bigger the better is not such a good idea. you will lose some low end power running an exhaust that is too big simply because you have very little back pressure
umm, ok..........

I did have 2.5" from the downpipe back......hated it.

I now have 3" right from the turbo back.
I wouldn't want anything else.
 

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exhaust

I have 2.5" down pipe with 3" after that. No cat. It's not too loud if your worried about that. I have a magnaflow muffler that sounds deep. I get compliments on the way it sounds all the time.
I have the stock turbo. Still spools up quick!!
 

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i have stock exhaust pretty much, but the cat is taken off has an open dump thing that i dont think even works and a gay ass fart can and i dont like it and i plan on getting 3 inch next spring no sence of doing it during winter since i live in michigan
 

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2.5 from the 02 back with no cat is just too loud. Believe me i've done it. Your best bet is 2.5 with a 2.5 cat. if you are running stock then this is more than enough
I had 2.5" from the turbo-back, no muffler and no cat, and it sounded pretty good. 3" IMO is just obnoxious, and 99.99% of the people on this forum will never make enough power to justify the need for an exhaust that big.:shrug:
 

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2.5" helps keep the engine's scavenging effect.
3" helps crossover, where intake mani pressure is higher than ex mani pressure.

I have heard tho, that all the exhaust in the world won't matter if say your turbine nozzle is too restrictive or other bottlenecks in the system. It would be nice see this part discussed since it seems more important than, "I have 3" and love the noise it makes".
 

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Both work- it just depends on if you like how it looks on paper. That pretty much sums it up.

2.5'' is plenty fo the power you will see out of a F2T engine with minor mods-

3'' is for BIG and I mean over 300 whp big- which you dont see on many F2T engines.

So its cars and karate kicks- people all have their opinion on sound vs practicality.
 
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