Removing the Cats

[33Bravo]

SS Ford Racing Headers (No Cats) and stock muffler .......The sound is intoxicating !!
Pull into a Cars and Coffee and watch the crowd gravitate toward the GT Symphony .

Interesting. I've asked the question here about putting on the stock muffler attached to long tube headers. I understand there is a weight penalty, but really wondered how that would sound (My borla setup is great. Now have a tubi style which is great but drones).

I am also interested in the flow of the stock muffler compared to the borla. On dyno day with Tori, we pulled 678 HP - how much HP (if any) would putting the stock muffler back (keeping the long tube headers)?

 

[Sinovac]

You can buy a cheap set of OEM cats and gut them.

 

[mmlcobra]

You can buy a cheap set of OEM cats and gut them.

I agree with this concept, however, I can't understand how a car like that could be "too loud".
And I'm way older then you J!
Best,
Mark

 

[MNJason]

So what does gutting the cats get me? Just less loud compared to a test pipe? The local shop is suggesting they fabricate something in place of the cats.

 

[nota4re]

I am also interested in the flow of the stock muffler compared to the borla. On dyno day with Tori, we pulled 678 HP - how much HP (if any) would putting the stock muffler back (keeping the long tube headers)?

I'd seriously doubt that there would be much if any HP penalty, if any. The main factor here is weight. The 52lb OEM muffler is a lot of weight in arguably the worst place it could be in the car - far aft and high. IMO, this should be the primary consideration (this and heat soak) versus a concern over 3-4 HP loss.

 

[PeteK]

I agree with this concept, however, I can't understand how a car like that could be "too loud".
And I'm way older then you J!
Best,
Mark

Mark, there is such a thing as "too loud." You should wait to hear other guys' cars and take a ride in them at the Rally or some other event before you do this. When a FGT is "loud," it's really loud.

 

[Sinovac]

So what does gutting the cats get me? Just less loud compared to a test pipe? The local shop is suggesting they fabricate something in place of the cats.

Sound will be the same, I was thinking about low cost and OEM appearance.

 

[mmlcobra]

Mark, there is such a thing as "too loud." You should wait to hear other guys' cars and take a ride in them at the Rally or some other event before you do this. When a FGT is "loud," it's really loud.

Sorry Pete, I can't buy that.
These are specialty cars for sure.
The choice is it going to be "quiet" or "loud"?
My car has no cats or mufflers.
The turbos do chill it a bit.
Best,
Mark

 

[MNJason]

Good info in here. Thanks for all the replies!

 

[mmlcobra]

Sound will be the same, I was thinking about low cost and OEM appearance.

Exactly!

 

[PeteK]

Sorry Pete, I can't buy that.
These are specialty cars for sure.
The choice is it going to be "quiet" or "loud"?
My car has no cats or mufflers.
The turbos do chill it a bit.
Best,
Mark

Mark, you know what you want. I'm not sure Jason does yet. Maybe he wants maximum antisocial noise and have to wear earplugs to preserve his hearing. Or maybe he actually wants to drive it on the street without waking up the dead and attracting unwanted attention.

 

[mmlcobra]

Mark, you know what you want. I'm not sure Jason does yet. Maybe he wants maximum antisocial noise and have to wear earplugs to preserve his hearing. Or maybe he actually wants to drive it on the street without waking up the dead and attracting unwanted attention.

Yes Sir!
But you don't go to the library to shoot a big bore firearm.
I DO get what you are saying.
Best,
Mark

 

[MTV8]

Removing the cats will also allow you to throw some pretty good flames from the exhaust.

 

[dpdive]

I have Fisher SS shorty headers, the cats are gutted and custom GT Guy SS X pipe. Entire exhaust system wrapped with inconel shields. At the track I am usually loudest. Rich Brooks said mine is louder then anyone's but it is still a wonderful sound.

 

[ChipBeck]

I have Fisher SS shorty headers, the cats are gutted and custom GT Guy SS X pipe. Entire exhaust system wrapped with inconel shields. At the track I am usually loudest. Rich Brooks said mine is louder then anyone's but it is still a wonderful sound.

Gentlemen,

These would be my choice if I had headers because they are one piece with no slip fits to leak.

Chip

 

[w.a.nelson]

As long as you don't replace the cats with a V-6, you'll be fine.

V-8 sound is one of the most intoxicating features of internal combustion engines, and the GT is among the finest in existence, no matter what configuration.

There will probably be one of everything at the Rally, so if you can wait, I would go along with the idea of sampling the possibilities directly. I'm sure the guys will cooperate.

Good luck with your choice. Again, you can't go wrong.

 

[MNJason]

Thanks again folks. I've been to a few rally's now and have heard a lot of configs. The one I like the best is the Ford Racing Headers with the FR exhaust. Since I am starting with my H pipe and OEM headers I was hoping to achieve a similar sound with not a ton of work. I think I'll start with replacing the cats with the "Borla Racing Muffler" which a link was posted to earlier and go from there. Thats assuming that these are more muffled then gutted OEM cats. Thoughts?

 

[mmlcobra]

I would go with gutted cats or test pipes until you get to the place that you are comfortable.
Can always quiet it later.
This will be the least expensive and easiest option to start with.
Best,
Mark

 

[Natee]

Removing the cats will also allow you to throw some pretty good flames from the exhaust.

Isn’t that why the Ford Racing/Borla muffler always have welding cracked when used with Ford Racing Long Headers (No CAT)?

 

[HOOKED ON GT]

I added the accufab pipe to the car after doing some short driving with just OEM cats exiting all the gas/sound....
It was loud but deep and sounded like a big capacity V8 with some off shore boat weight to it
Even the Accufab thats pretty minimal in restriction muted it down alot once I put it on.

Would love to know how a straight run from cats outback or straight up (like I pretended) and with 4" pipe would sound at WOT.

Love the ideas so many of you bring to the table.

Little drive in the GT with NO EXHAUST...OH YES!

With a curious mind and some custom heat protection for rear, I thought a little drive to experience some full audio rawness of what the GT can sound like with no exhaust should would be worth the effort. It was.... Didn't get to rip up through all the gears but the sound was Big Bang loud...

www.fordgtforum.com