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cutting exhaust behind cat

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 90K5, Sep 23, 2001.

  1. 90K5

    90K5 1/2 ton status

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    my leaf springs have broken the brackets that connect the exhaust pipes to the frame, so they bounce around all the time. I want to get the mrerouted to exit out the back, but don't have the money for that right now. I'm thinking about cutting the pipes where they bend down right in front of the gas tank, so they are pointing toward the ground, but they would exit about 2-3 feet before the rear of the truck, like dumps. Any drawbacks to doing this? I have a friend who cut his exhaust off, and could smell the carpet burning because of the fumes, but he may not have had a downpipe like I do. Also, will it affect the sound at all? Thanks

    90K5
     
  2. Pugsley

    Pugsley 1/2 ton status

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    It'll be a little bit louder, without a doubt. But, if you leave your top on, don't do it - your cab will constantly be filled with CO and other exhaust gasses.

    Special thanks to those lost from IAFF Locals 94 and 854 - You shall never be forgotten
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  3. 90K5

    90K5 1/2 ton status

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    Will it be filled with gasses because of the mgetting sucked in through the back, or coming up through the floor?

    90K5
     
  4. Pugsley

    Pugsley 1/2 ton status

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    A little of both actually - the gas will "pool up" underneath, and it'll find every little crack and hole to leak into the cab through.

    Special thanks to those lost from IAFF Locals 94 and 854 - You shall never be forgotten
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  5. blazing86

    blazing86 1/2 ton status

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    i have my exghaust like that and as long as the back window is up you can smell it at all. Sounds alot better without the tail pipes.
     
  6. Pugsley

    Pugsley 1/2 ton status

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    The problem there is the carbon monoxide - it's completely odorless and invisible, and will seperate from the other exhaust gasses. CO also will build up in your circulatory system and get you later on down the road. IMO better exhaust sound is not worth the risk of health problems or death.

    Special thanks to those lost from IAFF Locals 94 and 854 - You shall never be forgotten
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  7. 90K5

    90K5 1/2 ton status

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    I meant cutting behind the muffler, but I'll still probably leave it for now, and get them extended straight back a little later one, or maybe weld it back the way it is now.

    90K5
     
  8. jarheadk5

    jarheadk5 1/2 ton status

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    Whether you cut behind the cat or the muffler, you'll get more exhaust noise in the cab as long as the exit point of the exhaust is under the body. I've been running this way for a few months now (straight pipe off the cat, 45deg. elbow over rear axle) and it's noisy inside. I do get a lot of exhaust smell in the cab (from the rust holes in back) when I'm in slow traffic, but with windows down at 25-30mph and faster, it's OK.

    I wouldn't recommend this though; I only did it because my muffler rotted off and I can't afford a new exhaust system right now.


    September 11, 2001--"A date which will live in infamy"
     
  9. muddin4fun

    muddin4fun 3/4 ton status

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    It needs to exit away from the truck. You can cut it off behind the cat or behind the mufflers, but you'll still have fumes coming in.

    If you see my truck on a trailer, call 911 cause it's <font color=red>STOLEN!!!</font color=red>
    Website link is in my profile [​IMG]
     
  10. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Straight out the back will garrantee if you drive down the road with the back window down that you will gass yourself. Get them out the sides like they came. DO NOT LET THEM DUMP UNDER THE TRUCK.

    I don't need no damn shop manual, I got a pornographic memory.
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
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    Grim-Reaper
     
  11. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Man, I'm so glad I've got a truck instead of a Blazer when I read things like that.

    I have dual side exits anyway though, I think that the turndown idea doesn't work as well on lifted trucks anyway. Works great on cars and 2wd trucks though.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  12. Pugsley

    Pugsley 1/2 ton status

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    I always run side exits on my pickups - free and clear of dragging on declines, and just looks nicer to me.

    Special thanks to those lost from IAFF Locals 94 and 854 - You shall never be forgotten
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  13. dyeager535

    dyeager535 1 ton status Premium Member

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    Might I suggest (after overwhelming "don't do it'"!) that when you DO run side exits, make sure the tips are cut the way the factory did. Not only (IMO) does it look ten times better than a flat end, but it's probably also better to keep the exhaust away from the body.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</a>
    No anti-theft measures on your truck? No pity when its stolen
     

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