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post #1 of (permalink) Old 09-19-2003, 05:22 PM
kevin_z71
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EXHUAST

my 99z-71 has 2 cats running into the muffler. would it be tolerable to cut the muffler off and run straight out the back. local custom muffler man said it would be too loud, but i gotta question it.

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kevin
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post #2 of (permalink) Old 09-19-2003, 05:29 PM
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Re: EXHUAST

try it and see what happens. it all depends on how you like it.
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post #3 of (permalink) Old 09-19-2003, 07:04 PM
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Re: EXHUAST

dont know man, couldnt tell you thing about exhaust. had about 6 difrent set ups on my truck in as many years and im almost to the point to say screew it Im just way to picky.
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post #4 of (permalink) Old 09-19-2003, 07:47 PM
 
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Re: EXHUAST

Is it an old style z71 or new style? Because the 5.7 vs 5.3 will sound a lot different i think.

And if its an old style 99, its a "direct fit cat" setup, so the tubing with the cats bolts onto the rest of the exhaust system. Therefore, you could just crawl under there and unbolt the rear of the exhaust, and depending on how its supported, disconnect the rubber hangers and remove the tailpipes/mufflers completely and see how it sounds. It will be a little louder than running pipes out the back, and i wouldn't run with no tail pipes for very long, but it would give you a good idea what it is going to sound like.

I'm not sure where backpressure builds up in an exhaust system, but if its in the muffler/tailpipes, you will loose backpressure and your low end torque at the same time when you remove that stuff.

Sorry for the long post, hope it made some sense.....
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post #5 of (permalink) Old 09-20-2003, 02:36 AM
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Re: EXHUAST

only if you like a raspy ass popping exhaust sound that only gets more and more harsh when you get on it.

Go with the Flowmaster 40 series original FLOWS and youll be happy
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post #6 of (permalink) Old 09-20-2003, 06:47 PM
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Re: EXHUAST

I dont think it sound popy and farty with a mufflerless catback exhaust.
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post #7 of (permalink) Old 09-20-2003, 09:33 PM
 
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Re: EXHUAST

***begin sarcasm*** You should get some of those really cool 1" ricer mufflers for your rig! ***end sarcasm***



For real, dont run it without muffler(s), cause it will get old fast. For an exhaust system to work properly, you HAVE to have a certain amount of backpressure. Otherwise you will actually detrimentally affect your performance. Your computer is setup to change A/F ratios depending on a stock set of dependants. This is not so much of a problem on the older models as it is on the newer models. Newer computers need everything to be stock to be 'just right'.

BUT... thats not to say that you can't change certain things without affecting your computer system. i.e. - dont run without muffler(s). A nice set of high flow cats and Flowmaster 40's would be beneficial. This is because you are letting exhaust gases out faster, yet maintaining a reasonable amount of backpressure.

The people that get me are the ones that run JUST headers or open manifolds. People dont realize that they can do serious valve damage by killing their engine and letting COLD outside air to hit their HOT valves. This is one thing that valves dont take nicely to. I know a mor... I mean a buddy, that can vouch for this. Brand new set of high dollar Camelbacks... tard.... [img]images/graemlins/thud.gif[/img] [img]images/graemlins/spank.gif[/img] [img]images/graemlins/chair.gif[/img]
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post #8 of (permalink) Old 09-21-2003, 07:12 PM
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Re: EXHUAST

open headers or manifolds will usualy only screw valves up when its cold, and running no pipes behind the manifolds or haeaders off the motor. usualy,. or maybe running dual 5 pipes . Im being alittle sarcastic there. I dont know where you live but here it gets cold, sometimes ass low as -20 during high temps of the day. most everyone with pipes out the rear of the truck are safe. Ive had my exhaust come off at 10,000 foot elevations. at the crosover behind the manifolds without causeing damage. thats was at night with crystal snow on the ground, so cald the snow hangs in the air when you go through it, not much fluff. Im sure most of that was luck . but its not as comin as it may sound to hurt motors by sucking cold air to valves.
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