Cats are dead, gonna gut em, will need mufflers, which ones?

Fallenauthority

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So I killed my cats, which I knew I would, just was a matter of time, I have a Pypes catted x-pipe and I just recently installed my N2MB WOTbox, I know I know dont 2-step or NLTS with cats, well I did it a couple times cause I figured hey what the hell, I kill em, I'll gut em. So the other day I got a wonderful CEL for cat efficiency below threshold, so time to gut em.
However, I have SLP LM's on right now, I KNOW this will be retarded loud. I really like the way my car sounds now so I want to pick a muffler that will imitate the sound I have now with cats and no mufflers. Any suggestions? Also any performance issues possible with just gutting out the cats and throwing them back on instead of putting straight pipe in their place? I personally dont see a reason why it would but a couple people back when I had my old camaro said that if you just gut em, it jacks up the flow because the exhaust flows into an open space in the cat then has to go back down to fit into the rest of the exhaust. I dont think that theory holds too much water though.
Thanks for any input, I would do the buy and try approach but I could see that costing tons of money for me to find the right combo.
 

fdjizm

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How did you find out you killed them btw? anything besides the CEL?
I have a bassani catted x on the way and i've used my 2-step about a good 17 times testing launches, nothing negative yet, but I only use it for a half a second each time I'm not exaggerating I mean I don't even get to finish the word mississippi.
vacuum test checked out normal also. maybe you stayed on it way too long each time? obviously it's ill advised in general but I figured you wouldn't have killed them THAT quickly.
 
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Fallenauthority

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Well one day on my way to work last week I did a run from a light through 3rd using NLTS and when I pulled into my work parking lot I was greeted with a nice rotten egg smell and then when I drove it a couple days later I got the lovely CEL for Cat Efficiency below threshold, hence cat death.
 

Fallenauthority

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I was looking for a more bolt in solution lol, not trying to have to take it to an exhaust shop, I hate the idea of anyone but me touching the car.
 

killr3v

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No other choice really. You gut the cats, it'll sound like o/r midpipe. need another muffler before the SLP.
 

Fallenauthority

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No I think you guys got the wrong idea, I want to ditch the SLP's and use another axleback that would quiet it down a bit but still give me the sound I want.
 

BAKnBLK2010

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I would try your stock mufflers and see what they sound like with gutted cats. There are a couple of members on here running the stock mufflers with o/r h or x pipes and they say it sounds really good. Good luck!!!
 

fdjizm

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I was looking for a more bolt in solution lol, not trying to have to take it to an exhaust shop, I hate the idea of anyone but me touching the car.
I bought the bassani catted x off someone on here, it comes in 3 pieces so I can do it myself instead of needing to get the car on a lift :)
 

HEMI LOL

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ive got on O/R X with flows, and its not the best sound. at certain RPMs it sounds amazing, at others it sounds bad. chambered mufflers and no cats is a bad mix. straight through style mufflers sound better with no cats.
 

06silverbullet

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if i'm not mistaken gutted cats actually hurt performance due to the turbulance created when you open up to a bigger volume area(gutted cat) then back to the smaller diamter exhaust.
 

dascoyne

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you killed muffler cat?
muffler-cat.jpg
 

irishpwr46

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i have an off road h pipe with the ford racing stingers. it is pants shittingly loud at wot and pretty tame at idle/ cruise. its so loud that my camera has trouble recording the sound.
this is a fly by third shifting to fourth




ive got a few more on youtube if you wanna check them out
 

Fallenauthority

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I mentioned that in my first post, however I'm not sold on the fact that it hurts performance enough to make a noticeable difference between a straight pipe or a gutted cat.
Hell I believe it was lethalperformance who actually gutted cats on the stock midpipe of a 2011 gt for dyno testing when it came out and it of course increased hp.

if i'm not mistaken gutted cats actually hurt performance due to the turbulance created when you open up to a bigger volume area(gutted cat) then back to the smaller diamter exhaust.
 

HEMI LOL

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cats restrict power. they are a blockage. id get a nice O/R X or H and then do a mid mounted muffler. just do it right and forget the gutted cats bs.
 

DKS

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I would try your stock mufflers and see what they sound like with gutted cats. There are a couple of members on here running the stock mufflers with o/r h or x pipes and they say it sounds really good. Good luck!!!


Mine sounds really nice with the stocks and not cats

Put your stock mufflers back on and get an o/r H or X. They're cheap and easy to install
 

SirKnightTG

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They're cheap and easy to install


I've swapped my stockers on and off several times and I always found it to be a pain in the arse because they're so big and kinda heavy. At least, compared to LM or boomtubes or something like that.

I can take my boomtubes off and on in no time, but the stockers take me forever. It's hard to reach some of the hanger bolts due to the muffler's size.
 

fdjizm

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i have an off road h pipe with the ford racing stingers. it is pants shittingly loud at wot and pretty tame at idle/ cruise. its so loud that my camera has trouble recording the sound.
this is a fly by third shifting to fourth




ive got a few more on youtube if you wanna check them out
I think this is the first time I've ever said this, but your car is TOO loud :roflmao:
 

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