Exhaust Valves... say what?

Discussion in 'SRT Hellcat General Discussions' started by 16SRT, Jun 15, 2016.

  1. 16SRT

    16SRT VIP Hellcat Member

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    So, at this point, has anyone positively determined the operating behavior of our exhaust valves in each of the three standard drive modes? No guesses, post your evidence / cite your sources.
     
  2. Racist Cat

    Racist Cat Silver Member

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    My sources are from this forum. Users have reported how the exhaust sounds in different modes.

    I don't have any data.
     
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  3. carcass

    carcass SRT Hellcat Supporter Gold Supporting Member

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    I hate those valves,
    its so irritating!
    just the thought of them flapping around in there and clogging up and complicating the works of an otherwise beautiful exhaust system makes me sick to my stomach.
     
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  4. Racist Cat

    Racist Cat Silver Member

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    They don't flap. They are fairly precisely controlled. They are about 1/16" thick when fully open, and when closed, have a ~1/2" hole in them to allow air through. There is one valve per side.
     
  5. Bandit

    Bandit Gold Member

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    Do a mid-muffler delete. With that increased volume and new sound characteristic... you can't help but notice the huge difference at all speeds in Track Mode.

    I think the best way to put it is: they're open more than any other mode.

    I say that because honestly, while you're doing any driving, they're wide open, but put-putting around through your neighborhood, or pulling out of your driveway at an idle, they are closed. We know this because on a cold start, they are wide open, then as the car reaches operating temperature not only does the idle go down, but the exhaust further quiets.

    I often change between my custom mode and Track Mode and the second I get back on the throttle once in Track Mode, the difference is very noticeable.
     
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  6. sizzle06

    sizzle06 Silver Member

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    Thats why i had mine turned off
     
  7. 16SRT

    16SRT VIP Hellcat Member

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    Keep in mind that they may actually improve performance. I've seen too many guys put free-flowing exhaust on cars set up with street intakes and cams, designed to make torque at low RPMs, experience a loss in horsepower and torque when they were expecting a gain. The back-pressure these valves provide surely permit your car to build a little more torque at lower rev's, where we do 99% of our street driving. At high throttle, they open up to permit building higher HP at higher rev's, when your transmission shift points are also delayed into higher RPMs. The best of both worlds.

    If you want to improve your performance via free-flowing exhaust, you need the intake and cam to match, or in today's world... tuning. A street car set up to build power at low rev's will not typically benefit from larger exhaust, giving up valuable back-pressure where the car needs it most.
     
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  8. Radride

    Radride VIP Hellcat Member

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    How did you do this? Please explain.

    R.K.
     
  9. Mo-par!

    Mo-par! Bone Stock Hellcat Car Club

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    Agree, no max torque without the right back pressure...torque is the kick in the arse, not HP.
     
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  10. mdmoore23

    mdmoore23 Senior Hellcat Member

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    Wish they would've just gave the driver control of the exhaust sound like Ford and GM do with the exhaust on the Corvette and GT350.
     
  11. sizzle06

    sizzle06 Silver Member

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  12. Lumpy53

    Lumpy53 Silver Member

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    Noise is differant than a well tuned exhaust its music to my ears you do need back pressure for sure
     
  13. toplescuda

    toplescuda Silver Member

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    I could not hear any differance in that vid posted
     
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  14. MABBRYFL30

    MABBRYFL30 NYS President Hellcat Car Club Gold Supporting Member

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    I am not sure either but I will do some research. I do know mine fully opened and my cat is louder since I hit 500 miles
     
  15. Radride

    Radride VIP Hellcat Member

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    Agreed. You need a camera under the car on both settings to verify the valves are truly open.

    R.K.
     

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