Dual vs. single exhaust:

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Powell-Peralta, Apr 28, 2011.

  1. Powell-Peralta

    Powell-Peralta Road Train Member

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    Is dual exhaust quieter than single?
     
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  3. melpromud

    melpromud Medium Load Member

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    I dont think so. I think duels are just for looks anymore.
     
  4. Nitropickup

    Nitropickup Bobtail Member

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    There are soooo many variables that it's hard to generalize, but... In general a more restrictive exhaust in quieter and singles are in general more restrictive then duals. However duals can be easily made quieter without restriction and singles can be made less restrictive without adding noise.

    In motion, through a pipe, all the laws of hydrodynamics also apply to gasses.
     
  5. Donk

    Donk Have a Cup Of Concrete

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    Duals are useful where higher HP applications do not allow sufficent flow through quiet mufflers, so by adding two, flow is retained and noise kept down.

    in the real world, two pipes look better, but when the system rots out, cost more to replace.

    i have an ISX with twin stacks, and on a hard pull it heats up the pipes AND MUFFLERS enough to change the color of the steel. my mufflers are straight through units also.
     
  6. Krooser

    Krooser Road Train Member

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    The point of the biggest restriction will determine the ultimate flow of the exhaust... if you have two manifolds/split manifolds (one for each stack) duals make more power. But since you only have one pipe running from the engine a single exhaust will make as much power as duals.

    When inline diesels engines are put on an engine dyno they have a single exhaust... duals would do nothing to improve the HP...

    Let the beatings begin...
     
    Runnin Thanks this.
  7. Jfaulk99

    Jfaulk99 Road Train Member

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    I believe when the Acert first came out you couldn't order a truck with a single exhaust, the factory converters wouldn't flow enough. Only lasted like a year then they made larger converters. Didn't matter though most didn't stay on the trucks very long. You'd think they would build these trucks better, I know mine barely made it home from the dealer before those pesky things fell off.:biggrin_2559:

    For me it's dual all the way. Got one truck with a single stack and a single external air cleaner (w900) and it annoys me. Both are on the passenger side and it looks funny.
     
    07-379Pete Thanks this.
  8. Licensed to kill

    Licensed to kill Heavy Load Member

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    While what you claim is true, the problem with your hypothesis is that "the point of the biggest restriction" is the muffler and that occurs AFTER the Y in a dual application therefore the engine will only experience half of the restriction in a dual system.
     
  9. Flying Dutchman

    Flying Dutchman Road Train Member

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    In the cab, I have heard many drivers (for older trucks) say duals were louder.
     
  10. Krooser

    Krooser Road Train Member

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    Converters are a whole different ball game...

    If single exhaust won't allow a free enough flow why don't they derate the HP ratings on trucks with single stacks? Say it's 500 HP with twins but only 485 with a single exhaust? The answer is the duals don't make more HP... so the the HP rating stays the same.

    You can get a single muffler that flows more than 2500 CFM... that's a lot of air. Straight pipes will flow even more...
     
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