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Venturi-Assisted Exhaust System

No pressure, now...
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I'm sure you've noticed that many tailpipes have a sideways facing exit port, which I would imagine might very slightly improve the exhaust flow by the venturi effect; low pressure of the outside air relative velocity to that of the pipe helps exhaust suction and reduces horse-power loss.

My simple proposal is to design the exhaust port in such a way to maximize that effect. Instead of a simple exit pipe, optimize the airflow velocity around the pipe with some aerodynamically-shaped doohickie,* like an annular ring with a wing-shaped cross-section, for example.

Might gain a little horsepower, although a benefit-loss analysis would have to be conducted. I argue that the airflow underneath your typical car couldn't get much worse.

(*highly technical terminology reserved for usage by aerodynamicists, rocket scientists, and halfbakers).

RayfordSteele, Mar 18 2004

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       1950s technology - used to be a circular wossname that added a venturi around the rear facing tailpipes common then. Sold as a performance improver, called an Exhaust Extractor or similar, will try to find a link to an old ad for you.
unclepete, Mar 19 2004
  

       totally think there's a way to make it work   

       use your car's drag to essentially supercharge your exhaust.
imthatwillguy, Jul 17 2004
  

       if it dosen't cost too much money, a croissant on the house for you, RayfordSteele.
croissantz, Jul 17 2004
  

       Should have a small but still helpful effect. You could always put a turbo on the outlet manifold. Not necessarily as helpful as on the intake though.
wagster, Jul 17 2004
  

       Simple, but should help--if the engine is designed for it. In discussions like this I always point out that some of Honda's engines are actually optimized for backpressure in the exhaust manifold, and so actually LOSE horsepower if you do something like this. But they are an exception.
5th Earth, Jul 17 2004
  

       Much like a thrust augmentor like the ones used on pulse jets.
discontinuuity, Jun 21 2005
  

       If your going to do that why not just take the exhaust off compleately and so as the engine dosen't have to pump the gas all the way down a pipe.
Gendoikari87, Sep 03 2006
  

       I think most people would call a "annular ring" a "cone".
BJS, Sep 04 2006
  
      
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