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Uncapped Exhaust - Less power?

Discussion in 'Under the Hood' started by section525, September 30, 2002.

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  1. section525

    section525 sextion525 Elite Explorer Moderator Emeritus

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    Would this guy be losing back-pressure with is exhaust uncapped like this? Wouldn't his performance be worse? Or would it?

    This would be a trick setup for the track if you got a little more power out of it.
     
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  3. section525

    section525 sextion525 Elite Explorer Moderator Emeritus

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    Here:
     

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  4. jimbo74

    jimbo74 Elite Exploder

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    not bad for a jeep.... anyway.... it would hurt the low end but help on the high end....... it may trigger some wierd computer glithes though.... but it will sound mean as all hell...... personally, for best all around performacne... his flow 40 should be good enough unless he has some major power mods..... and that exhuast with the cutout is way illegal
     
  5. ld50

    ld50 Oh, the money you`ll blow Elite Explorer

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    I believe that most of your backpressure is caused by the catalytic converter.
    So If you have a non-restrictive muffler with larger diamater pipe on, like a cat-back install, you are close to being open after the cat anyway.

    My opinion would be that you would not notice any difference in performance, only sound.
     
  6. section525

    section525 sextion525 Elite Explorer Moderator Emeritus

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    After I installed my headers, I started the X up without the exhaust connected and it sounded AWESOME! Is it illegal to have a removeable cap like that in CA, or do you mean driving on public roads with the cap off?

    I just think it would be sweet for the drag strip. My dad's buddy has a mid-engine '56 Ford F100 and he has the exhaust caps like that. I've never heard it run, but I bet it sounds sweet.
     
  7. jimbo74

    jimbo74 Elite Exploder

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    Yes, very illegal--you may not get nailed for the fact you did it (although it is illegal) but will most likely get caught for noise violation and or modified exhuast

    my friends 468 chevy just runs headers with internal disc mufflers.... well they are removable and dont really silence it anyway... man that thing is awesome sounding.. just dont guide him into the trailer with no mufflers.... your brain will hurt and ears will ring ( i did that one day ;))
     
  8. section525

    section525 sextion525 Elite Explorer Moderator Emeritus

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    I already have a problem with lower end power.. so maybe I should stay away from this mod. At least until my current exhaust setup goes south! :D
     
  9. addkev

    addkev Well-Known Member

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    The guy is from Oklahoma, so he will probably never get caught, no inspections and lots of loud redneck trucks around.
     
  10. jimbo74

    jimbo74 Elite Exploder

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    See, the point I was making, was that to have the exhuast exit before the rear axle on any passenger vehicle in the COUNTRY is illegal. United States Department Of Transportation dictates that. In CA, we also have a law that states that no exhuast cutout devices (such as that Y) are allowed on any public roadway, ever. We also have modified exhuast laws that say the only modification that is allowed to be made to any exhuast must be made by an authorized dealer and cannot vary fdrom OEM design. The other one is the obvious noise pollution law.
     
  11. section525

    section525 sextion525 Elite Explorer Moderator Emeritus

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    Do these apply to pre-smog vehicles too? Such as that F100 I was talking about. Would that truck be illegal to drive on a public road?
     
  12. jimbo74

    jimbo74 Elite Exploder

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    the exhuast has to be behind the passenger cabin no matter what.... but the rear axle thing only applies to passenger vehicles.... the cab on a pickup truck counts as a passenger compartment.... having an exhuast exit before the rear wheels on a pickup is ok.... as long as it is behind the cabin of the pickup
     
  13. Alec

    Alec Elite Moderator Moderator Emeritus

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    I agree, that's after the cat so it probably doesn't make much difference, especially from the flowie and straight tailpipe. I didn't know it was illegal to have an exhaust cutout even if it was sealed on-road. I thought as long as it was capped it was ok, guess not. I do think that's stupid on a Jeep, because he could have exhaust infiltration into the cab.
     
  14. addkev

    addkev Well-Known Member

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    How does Saleen get away with side exits, the original Vipers and the older Corvettes?
     
  15. addkev

    addkev Well-Known Member

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    And....

    While I lived in Florida there are laws but no one is enforcing them. It is totally with in the norm to see mudder trucks running open headers or straight pipes.
     
  16. Perrin

    Perrin New Member

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    From my understanding of it the way that these cars get away with it is because their exhust will travel pastthe real axle and then return to the isde of the car to exit. I am not sure why this is better than just runnign the pipes there to begin with. However that is my understanding of the law.
     
  17. Mbrooks420

    Mbrooks420 High Voltage. Elite Explorer EF Vendor

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    They sell a y pipe that uses a pull choke style cable so you can open and close it from in the cab. They recommended it for highway use to improve gas milage. It was not recommended to use it all the time. Oh and I'm sure thats illegal also.
     






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