Shorty Headers


Fubar

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I am having a guy make me some headers that just replace the stock manifold and work with the existing catalytic converters. If anyone would like a set let me know. He is making them out of 323 stainless (that means nothing to me but he said it was the good stuff).

He works with Ferrari a lot so he understand the quality we are looking for.
 

soroush

Ford Gt Owner
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Aug 8, 2007
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whats he charging and when is your set going to be fabricated. pics?
 

Fubar

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The set will be between $1,500 and $1,800 (coating will be separate but I can get that done for $150ish). I expect him to be done by the end of next week. I will have him take some pictures of the entire fabrication process.
 

ChipBeck

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Shorty.

I am having a guy make me some headers that just replace the stock manifold and work with the existing catalytic converters. If anyone would like a set let me know. He is making them out of 323 stainless (that means nothing to me but he said it was the good stuff).

Fubar,

Doesn't Ford racing currently make a set of headers that will bolt up to the stock catalytic converters? I put a set of Ford racing shorty headers on my 4.6 L Shelby Mustang. I don't think they improve performance any but they look great. They required no modification to the existing exhaust pipes as they terminate in the exact same location as the stock cast iron exhaust manifold. This design necessitates the use of unequal length tubes. Is that the same thing that you're talking about building for the GT? Do you think there'd be any performance gain?

Chip
 

S592R

GT Owner
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Dec 3, 2006
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Chip,

I think FRP only makes long tube headers. Fubar and I where thinking (independently of each other) of this at the same time. The thought at this end at least was to be able to pull the cats out of the car if one chose to get rid of the heat back there. Also we both think the cast manifolds look like cr*p so in part it was for heat and beauty .... not sure if there would be a measurable gain in the HP arena.

Mark please chime in here if you think otherwise.
 
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nota4re

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Doesn't Ford racing currently make a set of headers that will bolt up to the stock catalytic converters?

Unfortunately, no. Ford Racing offers two different headers for the GT. One is their Rear Exit Headers which has two very small collector muffers (hardly mufflers at all) and exits the rear of the GT (hence the name). The other set of headers from Ford Racing is their Long Tube Headers whose length is beyond the OEM cats but their turn-up is in the same position and configuration as the outpt of the OEM cats so that you can use the OEM exhaust or any of the OEM replacement exhausts (Heffner, Borla, Accufab, etc.).

It would be extremely difficult to add cats to either system. :frown
 

jdoc7

GT Owner #1872
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Central, Illinois
I agree the stock cast manifolds do not look pretty, and that any type of header, whether shorty's or long tubes, would look much better. However, adding shorty's, in theory, should diminish torque in the lower RPM range with possible 5+ HP in the upper, doubt it'll even be felt on our cars. If it is worth the effort to you to change to shortys for sound and looks, then go for it. If you really are looking for looks and true performance gains, I'd go with the FRPP long tube headers. From previous posts of yours, you are deleting the cats as well. Your set-up is essentially a straight through system and will be VERY loud. What are your goals for your exhaust system?
 

californiacuda

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Oct 21, 2005
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With shorty headers the cats could be unbolted for race day and put back on for street driving. Sounds like a good idea. Headers usually flow much better than stock manifold. How much hp increase would need to be tested.
 

Fubar

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I suspect I will get more HP by dropping the cats but I will try to make Dyno test at each stage just for thoroughness. Understand that the car was not stock to begin with so the numbers will only be good for measuring change.

Deleting the cats was my original plan but when I found those cast iron manifolds... I was in a bit of shock. The idea that they would use a big hunk of iron on this all aluminum beauty caught me off guard. I would love for a GT engineer to chime in and tell me shorty headers are a bad idea and it would be interesting to find out why they choose the cast iron manifolds. So esthetics are higher on the list of reasons for this project than say HP.
 

Fubar

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What are your goals for your exhaust system?

I don't expect the header to play any roll in the sound. My original goal was to delete the cats with the Ford Racing Cat delete pipe. Thereby adding some volume. The FR Cat Delete pipe still has a small muffler on it and the system then runs into the FR exhaust canister. This system should be MUCH quieter than a straight through system. However, if it is to loud for my taste then I can simply add the cats back in.

So my goal was to have an exhaust system that I could change and tweak with minimal effort.
 
Last edited:

ChipBeck

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One question still unanswered.

Fubar,

Would the shorty headers that you are going to make terminate in the exact same location as the stock exhaust manifold so it could be a bolt in no modification swap?

And one new question. I was not aware that the stock exhaust manifold was cast iron. I thought they were aluminum. Has anybody weighed both exhaust manifolds and how much do you think the shorty headers would weigh? In addition to better aesthetics there could be a big weight savings here.

Chip
 

Fubar

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Fubar,

Would the shorty headers that you are going to make terminate in the exact same location as the stock exhaust manifold so it could be a bolt in no modification swap?

Yes it would be a swap out part.

And one new question. I was not aware that the stock exhaust manifold was cast iron. I thought they were aluminum. Has anybody weighed both exhaust manifolds and how much do you think the shorty headers would weigh? In addition to better aesthetics there could be a big weight savings here.

I wont know the answer to that until fabrication is done. I will weight them both for you.
 

nota4re

GT Owner
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Hey Chip,

This is the text from a post I made in June, 2006:

Ford Racing Rear Exit Headers Weight Savings:

Note: All weights were obtained using a better-quality digital bathroom scale. I assume that accuracy is probably within 1.0- 1.5lbs.

Stock Muffler: 55 lbs.
Stock Cats(Both): 29 lbs.
Stock Cast Manifolds (Both): 25 lbs.

Total stock exhaust weight: 109 lbs.


Ford Racing Rear Exit Headers/mufflers: 39 lbs. (complete)

Total weight savings: 70 lbs.


Also, note that the heaviest stock component is the muffler. In addition to its massive weight (stike one), is that it sits very high in the car (strike two), and, finally, as has been noted here, it blocks a substantial amount of airflow (strike three).

The Rear Exit Header System, by contrast, is not only much lighter, but the weight is also lower. The header tubes pass UNDER the halfshafts and then the collector mufflers are almost at the same height. There is now literally nothing behind the airbox. No more heat soak. Good-bye 70 lbs!
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
The Rear Exit Header System, by contrast, is not only much lighter, but the weight is also lower. The header tubes pass UNDER the halfshafts and then the collector mufflers are almost at the same height. There is now literally nothing behind the airbox. No more heat soak. Good-bye 70 lbs!

Good-bye to your hearing too!
 

jdoc7

GT Owner #1872
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Jan 7, 2007
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Central, Illinois
Good-bye to your hearing too!
LOL!:rofl:rofl
 

nota4re

GT Owner
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What?
 

Gulf GT

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Good-bye to your hearing too!

What?
 

Gulf GT

GT Owner
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Feb 9, 2006
1,539
California

Tie goes to the one with more posts...Oh well.
 

Fubar

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I just weighed the cat v/s cat delete pipe (on a bathroon scale :biggrin).

Pipe w/ cats = 15lbs
Pipe w/o cats = 9lbs

Total savings there is roughly 12 lbs

I would be surprised if you save more than a pound or two with the headers v/s manifold. There just isn't much there to work with.


-Anybody know the weight difference between the stock muffler and the Ford Racing muffler (canister)?
 

nota4re

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I expect him to be done by the end of next week. I will have him take some pictures of the entire fabrication process.

The guy is a friggen' magician IF he can pull this off.