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Gutted cats yes or no?

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Old 04-13-2004, 12:46 AM
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Default Gutted cats yes or no?

I was thinking about doing this until I could afford to get some headers and offroad y-pipe. My question is how will the exhaust sound and about how much horsepower is this worth. Also what would be the best way to go about doing this? Thanks for the help.
Old 04-13-2004, 12:53 AM
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Just wait for your mods. I don't think gutting them will yield too much (5 ponies maybe on a near stock setup). I have gutted 3" cats. They were gutted post-headers (not by choice, they fried, then we just finished gutting them out). I also kept them on in case anyone checks under the car for a visual inspection.
Old 04-13-2004, 01:27 AM
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Don't even bother. Just wait for the offroad y and headers.

You will pick up next to nothing, and it is a decent amount of work.
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Old 04-13-2004, 09:42 AM
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I had gutted cats for a week or so when I had stock manifolds. Didn't notice any difference except a little louder exhaust note and some rasp. I also had at one point the Mufflex off road pipes for the stock manifolds. With those, I felt a small improvement in power, exhaust was alot louder, but also very raspy in the 2000-3000 rpm range...even with my Hooker catback (which is suppose to be one of the best at not having rasp). I now have longtube headers and I wouldn't have it any other way. Car sounds the best it ever has and I picked up good improvement in power.

Moral of the story....wait for the chance to get headers.

P.S. Also, if you decide to gut them anyway, remember to get 02 simms for the rear 02's so you don't set off the SES light.
Old 04-13-2004, 10:45 AM
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Default Don't gut your cats....

Don't do it! Just buy a cat back exhaust and a new y-pipe, with offroad inserts. That way, you will have some cats to put back on the car when you go to sell it.
Buying CATs are not cheap. But you could go the high flow CAT route, like I did. I think I paid about $300 a peice, for high flow 3" CATs from Random Technology. They are cheaper now, that was 3 years ago. Of course, you can find cheaper ones, for around $110 each. The key is, you will need them when you sell your car. And, some day, you will sell it.
Enjoy it in the meantime.
JC
Old 04-13-2004, 11:59 AM
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if you already have a catback and cant spend $500+plus on headers and Y pipe then consider spending $200 or less replacing the flattened Y pipes and gutting your cats. I say you gain at least 10hp with that combo. Headers usually yeild only bout 10hp more. Not everyone has $1000 to spend on an exhaust, headers, y pipe catback and installation. most of the stock bottle neck is in the cats and the flattened y pipes, once again if you already have a catback it make more sense. jut my .02 cents

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Old 04-15-2004, 10:31 PM
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Originally Posted by Red346
I was thinking about doing this until I could afford to get some headers and offroad y-pipe. My question is how will the exhaust sound and about how much horsepower is this worth. Also what would be the best way to go about doing this? Thanks for the help.
Any reduction in restriction in your exhaust will yield power. Thats why John Force doesn't have any. There is such a thing as too much of a good thing. AS your exhaust gets so efficient, at low speeds it can actually pull some of your intake charge out the exhaust. so it can hurt low end torque, but will yield high end power. The closer the restriction is to your heads, the more impact it has on performance. The Cats are a HUGE restriction. gutting them will yield something but won't fully be realized cuz you have restrictive manifolds instead of headers, but it will help. I gutted mine the old fashioned way, I just ran rich until it ate the cats from the inside out raw fuel dissolves the cats, but a hammer and a big ol' screwdriver can work wonders
Old 04-15-2004, 10:37 PM
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Originally Posted by 2000Z28M6
if you already have a catback and cant spend $500+plus on headers and Y pipe then consider spending $200 or less replacing the flattened Y pipes and gutting your cats. I say you gain at least 10hp with that combo. Headers usually yeild only bout 10hp more. Not everyone has $1000 to spend on an exhaust, headers, y pipe catback and installation. most of the stock bottle neck is in the cats and the flattened y pipes, once again if you already have a catback it make more sense. jut my .02 cents

More power is to be had from the headers than anywhere...

The stock cats also flow VERY well....somewhere ( I think on here) someone has done a flow comparison of stock cats and many aftermarket ones...stock outflowed some aftermarket cats.

I replaced my stock flattened y and cats with a MAC ORY and did not pick up all that much power. Long tubes and ory is the best way to go if you are looking to get rid of cats. Might as well pick up 30hp instead of 5-10...


Chris
Old 04-16-2004, 01:01 AM
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How do 2 tenths is the quarter sound? Thats what a friend of mine got by gutting his cats.
Old 04-16-2004, 05:00 AM
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if i were u i'll wait
Old 04-16-2004, 09:07 AM
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Just get your local muffler dude to make you some pipes that bolt in place of the CATs. That way u can put them on when u need inspection. My local guy is going to charge $160. Im gonna do it next weekend.




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