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Thread: What do you think and gains here.

  1. #1
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    What do you think and gains here.

    I didn't like how the wastegate would disrupt the exhaust flow and probably cause some lag. So I ran a 1" pipe, through the elbow and extended it to isolate the wastegate. Thoughts?
    Turbo wastegate outlet.jpg
    Turbo wastegate outlet1.jpg
    Turbo wastegate outlet2.jpg
    Turbo wastegate outlet3.jpg

  2. #2
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    Wow unknown in America 89 people and not one opinion!

  3. #3
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    Lag? That is normally a term used for how long it takes to pressurize the intake, yielding the power you’re after. The wastegate is a bypass for the excess exhaust gasses as the pressures inside the intake reach your prescribed limit. The wastegate has no influence on turbo lag unless it is leaking. How’s that?

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  5. #4
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    Thanks for the response. Good, but and I am a novice at understanding the finer points of turbos.. On my 2.0FSI Audi. I would run at the max boost level across much of the RPM range. The N75 would be at like 60% to 95% duty cycle to keep me there. Doesn't this mean that the wastegate is opening and closing to maintain the boost at the set level? If that is the case wont it be more effective if I am not disrupting the exhaust flow path. I was told remote Wastegate were more efficient. Is this not the reason? I am just trying to have a discussion.

  6. #5
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    This is why I did what I did. " As the flow passes between the port and wastegate valve it is accelerated and if not directed correctly can cause an aerodynamic blockage to the bulk flow leaving the turbine wheel". Was hoping for some good discussion on this board is all. " Efficiency losses to the turbine stage which are caused by this disruption are described as wastegate flow mixing losses."

    Capture.JPG

    https://www.cummins.com/sites/defaul...egate-flow.pdf
    Last edited by Brd.Prey; 10-02-2019 at 07:02 AM.

  7. #6
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    You aren’t wrong about flow interruption. External wastegates generally have a discrete dump tube partially for this reason. Since your added fin is on the exducer side, it probably won’t hurt anything if it should dislodge. I doubt that you will feel a difference in performance. Some turbo applications don’t use a wastegate at all. The availability of various a/r ratios has made it possible to match turbo output with engine capabilities. This is more common on stationary engines that don’t change rpm often. My friend matched his turbo to a 4 cyl iron duke engine in his boat. It consistently outran more powerful boats. A sleeper, you might say.

  8. #7
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    “Turbocharging” by Hugh McGinnis. It’s an older publication but the principles still apply. Get it. Read it. It will explain far more than you will learn here.

  9. #8
    Senior Member q4stix's Avatar
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    It's hard to tell from the pictures, but it looks like your wastegate flow is a continuous curve but it angles into the main turbine output flow. You want this to be the opposite where there is a continuous contour after the turbine for smooth flow and no drastic changes in exhaust cross section. Hope this makes sense
    Gen 3 Type 65 Coupe builder

  10. #9
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    Looks pretty similar to the aftermarket divorced wastegate downpipes. I’m a huge fan of the external wastegate though.

  11. #10
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    Not as good as external wastegate but 10 times better than that flat plate over the wastegate!

  12. #11
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    Quote Originally Posted by walt555 View Post
    Not as good as external wastegate but 10 times better than that flat plate over the wastegate!
    Thanks, pretty much what I was thinking. That flat plate section looked horrible.

  13. #12
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    Another book that might interest you is MAXIMUM BOOST by Corky Bell.

  14. #13
    Senior Member Blwalker105's Avatar
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    That looks pretty beautiful, Brd.Prey...enough so that I just may copy it after looking at the horrible flat plate piece just last Thursday. Nicely done.

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