Audi s2 turbo surge????

[smh]

Has anyone heard this noise before ? This is my own vid I took while testing like to see what people think it can be
https://youtu.be/FmseDroHX1k

[Quattronaut]

May also be a ripped diverter valve. At what rpm and throttle do you have the sound, what turbo and setup? Is there a boost gauge?

[M_GORDON]

Yes, it seems a broken diverter valve

[Costash]

It s on boost think coils are playing up.... worth checking

[smh]

Yes I was having trouble with this issue for a long time , in my case it was the turbo that was loose against the manifold after tightening it , the whistling sound went away ... The spec of the car is in the YouTube description

[Prosac]

I have the same problem with an RS2 with PT6766. 2bar and this flapping noise including boost pressure. from 5500rpm it's gone but between 1ba and 2 bar is cruel to drive.