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So there is a fair amount of content on here regarding the unplugging of a diverter valve to create the turbo flutter however almost all of it has conflicting answers, some say it's not too bad and there's cases of them having it unplugged for like 40,000 kms with no issues and so far I've seen no one say they've had an issue as a direct result of unplugging it.

So basically is there a clear answer as to why unplugging it is a bad idea?
 

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Unless Audi made major changes that I am unaware of the DV is essential for turbo responsivity. When boost is high but demand falls and the throttle valve closes, the pressurised air is diverted back to the turbo inlet. This prevents back-pressure that could stall the turbine, and in fact the diversion actually keeps the turbine spinning by maintaining airflow. Then when demand is created again and the throttle valve opens the turbine is spinning and ready to create boost again. So stopping the DV operating will create backpressure which will result in hesitation in the boost.
 
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As Dippy says, what you are effectively doing is pressure opening the DV valve, which is what causes the flutter noise. I'm no turbo expert, but I guess this is the noise of the turbo being stalled by pressure? You hear this noise if you manage to get a bit of turbo spool, like a hill start, but stall the engine. The DV will still be shut as the throttle was still open at point of stall. The plugged in valve will release the pressure when the throttle is closed and smoothly transfer it back into the intake.

In my opinion, you may see no faults, but you could be loosing out when changing gear as the turbo will need to spin up again. May sound good, but I very much doubt you will see a benefit, more negative.

What about an atmospheric dump valve? Or even an open cone intake will give you some fluttery turbo noises?
 

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I believe that there are devices that can imitate the sound of a BOV.
 
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