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Varg In Jeep's Clothing

Discussion in 'Builds and Fabricators Forum' started by ITLKSEZ, Aug 20, 2015.

  1. Sep 26, 2019
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    I hear urine is as well.....
     
    Rich M. likes this.
  2. Sep 26, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    While I’m waiting for the fuel pump situation to work out, I’m starting to think about the muffler. I have very specific spots where the inlet and outlets need to be, so I really have no choice but to build one from scratch.

    The old muffler I have from a Volvo 850 is close to what I need, but not close enough. It’s square, flat, and really quiet. I decided to cut it open to see what’s inside; to see if it’s a design I want to replicate.

    [​IMG]

    It was packed with fiberglass that has disintegrated over the years.

    [​IMG]

    Inside the fiberglass is an “S” of perforated tubing. This is referred to as an “absorptive” muffler, one that uses packing material to absorb sound.

    [​IMG]

    I think I will copy the direction of the flow, but utilize a “reactive” design instead. This design (e.g., Flowmaster) uses baffles to cancel the sound waves out, like noise cancelling headphones. It has no packing to degrade, and has good flow if designed right. The key is to figure out (or get lucky, like I'm hoping) how to design the chambers to cause destructive interference...

    [​IMG]

    ...rather than constructive interference, making it louder, or "raspy." That clapping noise you hear in some exhausts is the sound impulses piling on top of each other. I don't want that.

    [​IMG]

    If I use the "S" shaped path, I can essentially make three mufflers inside the box, each with different angles to cancel different frequencies.
     
  3. Sep 26, 2019
    Dphillip

    Dphillip Member

    Omaha NE
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    Nov 25, 2008
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    322
    It’s now official, you are totally out of control!
    I think an intervention is now in order.
     
    Twin2 and Focker like this.
  4. Sep 26, 2019
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    I had the same idea, but abandoned it when I found a set of discarded stainless mustang mufflers in the trash... Haha no, just kidding. I never thought about building my own muffler. Get to it!
     
    fhoehle, Focker and ITLKSEZ like this.
  5. Sep 26, 2019
    Admiral Cray

    Admiral Cray I want to do this again.. Staff Member

    Bainbridge...
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    Two words... Open pipes...
     
  6. Sep 26, 2019
    SoCalNickG

    SoCalNickG Member 2023 Sponsor 2022 Sponsor

    Whittier, CA.
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    Please hold off on the intervention until he is finished with the jeep!:sneak:
     
    Dphillip and tomasinator like this.
  7. Sep 26, 2019
    '74Renegade

    '74Renegade Active Member

    Fair Oaks, CA
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    I don't think "flomaster" and "noise cancelling" belong in the same sentence.
     
    fhoehle and ITLKSEZ like this.
  8. Sep 26, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    Flowmaster is more relatable than “stock Honda Civic,” but same concept... :D
     
    '74Renegade likes this.
  9. Sep 26, 2019
    73 cj5

    73 cj5 Not ready for the junkyard yet

    Clinton, Mississippi
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    Jan 10, 2014
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    I like your style. Daily driver it’d be miserable but off road toy,,, doable.
     
  10. Sep 27, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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  11. Sep 27, 2019
    FinoCJ

    FinoCJ 1970 CJ5 Staff Member

    Bozeman, MT
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    was that a double fist pump?
     
  12. Sep 27, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    It was a, “It’d better have worked, or Hulk smash!”
     
  13. Sep 27, 2019
    47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    USA
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    Now, wait... where's that ignition switch to turn it off.. Oh yeah..

    Killer man!!!!
     
    ITLKSEZ likes this.
  14. Sep 27, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    The back-story, now that I have a minute...

    I got the new fuel pump, and it didn’t help the situation. I started digging into the fuel rail, and I found that three of the four injectors were good, but one was stuck shut from sitting. I threw it in a jar of mineral spirits and shook it, then it started to click lightly when I’d hit it with 12v. I kept working it, and it freed itself. Great, but unrelated.

    This system works by applying a constant 12v to the injectors, then the fuel ECU supplies a ground pulse.

    Fuel pressure was good, the injectors worked, there was a constant 12v, but there was no ground pulse. It took all day with the wiring schematics to figure out there was a single ground wire up by the right front turn signal that I hadn’t hooked up. It feeds ground to the ‘radio suppression relay’ near it. Technically, the pumps shouldn’t have worked either, since that feeds the power to them too, but whatever.

    I’m glad this happened; I learned a lot about how this system works. There’s no better way to learn something that to just dive right in. Do it!!!
     
  15. Sep 27, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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    I’m extra happy that this worked because the engine is from an ‘87 automatic 740, the transmission is from an ‘82(?) 240, the distributor, clutch and flywheel was from a turbo 940... I wasn’t sure if everything was going to play nice. So far so good.
     
    Twin2 likes this.
  16. Sep 27, 2019
    mortten

    mortten I can’t put my finger on it 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Peninsula, Ohio
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    Almost everything is ground switched anymore. Sounds good. I don’t think you even need a muffler :)
     
  17. Sep 27, 2019
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
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    The ear muffs was a nice touch :D
    sort of reminds me when I first fired up jeep after body off for a few years :whistle:
    dawg had hung out with me in garage for months , while I worked
    only time I would kick her out was when I needed to do some welding
    when I was doing the wiring under dash she would jump into jeep . and pounce on my stomach . to get my attention
    all was well till the day came . to see if it would run . open headers
    her interest about hanging out in garage . is long gone . all I have to do is act like I am going to start jeep or motorcycle
    no more dawg . she hides out by trash cans at other side of yard
     
  18. Sep 27, 2019
    ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    Liberty Lake, WA
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  19. Sep 28, 2019
    fhoehle

    fhoehle Sponsor

    Harford Township, PA
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    I am overwhelmed with the progress! It is incredible! As usual, the work is beautiful.
     
    ITLKSEZ likes this.
  20. Sep 28, 2019
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    The only onion in your ointment is that your design will only work for one fundamental frequency & even multiples thereof, nor are exhaust pulses, being rather explosive events, nice pure sine waves.

    Bose & other sound cancelling devices work by splitting the audio spectrum up into lots of rather narrow 'bands" & applying the inverse sound to these on an individual basis.

    Mufflers work more by like a gun silencer- taking the energy out of the sharp explosive burst & spreading it out over time both by both removing heat from the gasses & by allowing the sound waves to echo around inside for a bit as they run out of steam.

    If you know someone in a hospital maintenance department get them to let you have a look at their standby genset baffling system for the room ventilation- I've seen system you could literally see through but on the inside you couldn't stand there without ear defenders, 3' away on the other side of the vent normal conversation was a non-issue.
     
    ITLKSEZ likes this.
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