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Where's your Muff???

Discussion in '80-Series Tech' started by Shoppy, Oct 22, 2017.

  1. Shoppy

    Shoppy

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    Hello All,

    I am Building an 80 LS1 swap with 75mm Slinky lift and 37's and need ideas for exhaust routing, Muffler and exit points... Aggressive or plain I'm dying to know what you got

    Gracias
     
  2. Shoppy

    Shoppy

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    Here's what I'm working with. Looking for your pics

    IMG_7928.JPG
     
  3. gummycarbs

    gummycarbs

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    I've always wondered why people don't dump the exhaust ahead of the rear wheel.
     
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  4. Fj81

    Fj81

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    This thread title should get interesting replies... mine is still stock, but it is sticking out alot back there. It will have to go soon. OI000151.jpg
     
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  5. LandCruisinMy93

    LandCruisinMy93

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    My muff is just sloppily dangling beneath the undercarriage slapping away at the sides. It makes a whistiling and flapping noise when I pick up speed too. Of course that's what happens when a big ole gal gets rid of the cats, she loses that connection and everything just goes down hill and the muff just dangles there disconnected waiting for somebody to come along with a a big enough pipe to fill the gap and get her humming again. Until that day comes she's just going to be big and loud and annoy everyone around her....remember that you brought this on yourself. I am referring to the fact I just did a motor swap and haven't done exhaust work by the way.
     
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  6. JaketheSSnake

    JaketheSSnake SILVER Star

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    I wouldn't mainly because I use the rear sliding windows from time to time, it'd probably make it a lot louder inside too. On something that sees more offroad use than on, it might not be a bad idea.
     
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  7. dannyp

    dannyp

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    I can't be too much help on your routing from the V8 but I have two and a half inch pipe back to a single 40 series Flowmaster in the same location the stock Muffler was in and it is tucked in real nice. I have it dumped out just rear of the rear tire. Have only been Wheeling once with it so I don't know at this point if I will need to trim it back some more so it doesn't get banged up where it sticks below the frame but it won't be very hard to trim a few inches off of it
    i do have a 1" body lift so up and over the frame was easier than it wouldve been without the extra inch

    20170904_093939.jpg

    20170904_093950.jpg

    20171023_133455.jpg
     
    Last edited: Oct 23, 2017
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  8. zonker

    zonker

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    @gummycarbs Here are three good reasons to terminate further back. The distance from the back of the cats to the front of the rear wheel would not leave enough room for a real muffler. I can only imagine how loud that would be.. right below the passenger rear door. Running the pipe to the opposite side to gain distance for a muffler could only be short of a real pain.

    The second reason.. unless you extended the open pipe out from the rocker a good distance.. at idle or going slow there would be a lot of potential for the exhaust to creep into the cab. Door seams.. worn weatherstripping.. etc.

    Last but not least. Should you start to use your LC someday and you are in good sized rocks they will be dragging along the underside of your slider. Rest assured before your rear wheel climbs up and over the rock your exhaust pipe will definitely get smashed closed. Not a good thing. Unless of course you have a mega-lift and not the 2" you have installed.

    Generally an open end of the exhaust somewhere close to behind the wheel won't be so vulnerable. As you come down off of a rock.. the forward momentum might move the vehicle forward and hopefully helping clear the pipe. I did see a 4x4 Labs bumper where the pipe exited thru one of the lightening holes on the underside. Just barely was the tip poking thru.
     
  9. Shoppy

    Shoppy

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    Thanks to give of you who posted pics of your exhaust. They were all good suggestions. I didn't get much response on creative exhaust ideas tho, like out the side of the Body or through the bumper etc... The open headers I started with were awesome and I kept them for later use. I was very lucky to have a friend who has a welding shop, he let me spend a Sunday on the rack and pipe bender. This was my first time creating and exhaust system. wound up using some block hugger manifolds and cut some pipe at about a 15 degree angle and turned the header flanges towards the direction I went with the y pipe. I added V band flanges so they seal forever. The 3 bolt flanges headersbcome with suck. I then ran forward On the passenger side, under the front of the engine oil Pan and headed back. Added Y connection at the driver side and down the inside frame rail. The turned up over the transfer case and headed back to the muffler in the stock location. Pretty much went back as did the stock tail pipe.
     
  10. Shoppy

    Shoppy

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  11. Shoppy

    Shoppy

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    Open headers IMG_8024.JPG
     
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  12. Shoppy

    Shoppy

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  13. Shoppy

    Shoppy

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  14. Shoppy

    Shoppy

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  15. gofast

    gofast

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    Nice job!
     
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  16. Dubbinchris

    Dubbinchris

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    What front drive shaft is that?
     
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  17. Shoppy

    Shoppy

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    We don't really have a good driveshaft shop and was having trouble finding a taco shaft so I ended up with a Tom Woods custom driveshaft. Worked out great. All new and fair price with all things considered.
     
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  18. Mandrake

    Mandrake

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    I have some cheapie Autozone muffler in place of the stock muffler, and I decided to just put a down turn on the back of the muffler and call it good.

    It's louder, but I think primarily because the sound is reflected back up off the pavement and bounces off the bottom of the truck.

    It's not any smellier. In the nearly two years of street and trail use, I've never caught a whiff of exhaust. However...

    Because the exhaust outlet is pointed down, it blows a ton of dust everywhere and if my windows are down and I'm not driving in to a headwind, the cabin gets filled with dust.

    I did it in a pinch and on a budget at the time, and haven't ever done anything about it because I still have this plan in my head of either going turbo or running the exhaust completely inside my frame (having a 1" body lift helps with this plan).
     
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  19. GW Nugget

    GW Nugget I need to stop messing with it & just drive it!

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    Cats?
    That's the big delima.
    Great work bye the way, better than I could do.
     
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  20. Shoppy

    Shoppy

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    Thanks GW So the cats will need a different set up for sure. Probably going to be tricky with the front driveshaft and a lot less functional for offroad. But I do have plans to flange a few spots so I can install cats that are referee kosher. Also will need to choose some CARB manifolds that will work. In this case I was just happy to get it to turf n surf. Smog stuff later
     
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