2 1/4" or 2 /12" Flowmaster cat back?

MadMatt5oh

Member
Jan 10, 2003
441
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16
St Paul, MN
Hey people, sometthing terrible has just dawned on me. A few months ago I bought 3" long tubes with 2.5" reducers and a 2.5" o/r H. I havent driven my stang other than the initial ride home yet. I dont have a way to get under it far enough either! I know I have 2c flow catback with 2.5" tips. But Im worried that the stock exhaust of 2 1/4" will leave me with only a 2 1/4" catr back. My buddy says thats not true. That reducers had to have been used because flowmaster doesnt make a 2/4" cat back!

Is that true? If so, then I will have to get the cat back too because I dont want to bottleneck my performance making my upgrade worthless!
 
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They do make a 2 1/4" system, cuz my friend has it on his car. As for the 3" long tubes, do you mean they have 3" collectors? Cuz if they do, it could be a bit of overkill on your car, and could actually hurt your performance. Check out the list on my car. And my headers are 1 5/8" primaries with 2 1/2" collectors.
 
I think your smokin' crack. You are replacing everything in front of the cat-back that is on there, right? You already have a flowmaster cat-back that is 2 1/2" on there, right? If this is all true, then there will not be any of the factory exhaust left on the car.....what's the problem???
 
Ok guys.. this is what he is saying..

Bought headers with 3" collectors, and a 2.5" h pipe... he has 2.5" tailpipes with flowmaster mufflers, but he doesnt know if the flow tubes/mufflers are 2.25" or 2.5" - he wants to know if flowmaster makes a 2.25" catback.

Yes flowmaster does make a 2.25" catback, so your going to have to find a way under your car to find out what you have.
 
Mavrick said:
Ok guys.. this is what he is saying..

Bought headers with 3" collectors, and a 2.5" h pipe... he has 2.5" tailpipes with flowmaster mufflers, but he doesnt know if the flow tubes/mufflers are 2.25" or 2.5" - he wants to know if flowmaster makes a 2.25" catback.

Yes flowmaster does make a 2.25" catback, so your going to have to find a way under your car to find out what you have.



What does it matter, then???? If the flow tubes ARE 2 1/4", they will bolt up to the 2 1/2" h-pipe, no problem........... :bang:



.
 
Ok, Guy's after reading that I'll clarify!

My my has stock headers and H. Those are 2.25

It also has a Flow cat back which I wondered what size it was and still dont know.

The former owner was a Moron but took good care - just could have made better choices.

I have long tubes and a o/r H sitting in the closet.

Long tubes: 1 5/8 primaries with 3" collectors with 2.5 slip in collect reducers.

Mac o/r shorty H at 2.5

Is it possibel Numbnuts has a 2.5 cat back? I can't check for at least a month
 
MadMatt5oh said:
Ok, Guy's after reading that I'll clarify!

My my has stock headers and H. Those are 2.25

It also has a Flow cat back which I wondered what size it was and still dont know.

The former owner was a Moron but took good care - just could have made better choices.

I have long tubes and a o/r H sitting in the closet.

Long tubes: 1 5/8 primaries with 3" collectors with 2.5 slip in collect reducers.

Mac o/r shorty H at 2.5

Is it possibel Numbnuts has a 2.5 cat back? I can't check for at least a month
what are the reducers for you dont need them my bbk long tubes bolt up fibe without that stuff. :shrug:
 
Even if it is a 2 1/4 cat back it's not going to bottleneck your car with the list of mods you have, that what I have on my car and it's perfect. The only thing that you have to remember is that you choose parts that are mandrel bent, because if they aren't than you are dealing with a 2 1/4 pipe anyway because the bends are collapsed from 2 1/2 to 2 1/4. So if the guy got 2 1/4 mandrel bent tails then it would be just what you need, the intake and heads on the 5.0 are the most restricting.
 
Thanks Guys,

Yes, I have a shorty H.

I'm not sure if my pipes are mandrel bent or not. The tail outlet is 2.5".

My fears are at ease I will keep my exhaust parts and 2 c flows.

My tails are painted blk on a blk stang so they keep me under the radar. I'll keep it that way this year and worry about cosmetics this year.

Chrome tails, about 2k of mods and cosmetic enhancements next year! :nice: