Then your wastegate is opening/stuck open. And seeing that you have it disconnected then that means Wilde was correct and that the wastegate is stuck open...just get a new one or try to fix the one you have!!

 

I have successfully tore down, cleaned, and lubed (with a VERY good anti seize) my waste gate. I have about 5,000 miles on sence I last tore it down, with no issues so far. I can post some pictures if you'd like.
The waste gate has to deal with water and being in a remote location AND being mounted in such a way water will saturate the waste gate valve and stem, rusting can occur. The waste gate will start to get "lazy" then it will stick. When Mine did it (with the sts) I wouldn't have boost until 4500 or so and would only have a couple pounds of boost.

The easiest way to tell if the waste gate is stuck if your duck call doesnt work when you let off the gas...

 

Ha ha, duck call...what do you mean, compressor surge, turbo bark?

 

30mph roll video waste gate flutter.. not to be confused with turbo bark

 

Here's another version of if, pay attention after we lift off the throttle, you can hear the duck call.

http://www.youtube.com/watch?v=Xw0FH5uKlgI

 

Oh...not to be confused with this either...
http://www.youtube.com/watch?v=VbNxugO-uf0

 

Check for:

Exhaust leaks pre-wastgates
Charge pipe leaks
Wastegate function AND setup -- make sure the WGs are plumbed correctly, and that you don't have big huge diameter vac lines.

Mine did the same thing initially -- I have a small diameter fuel line on because I'd run out of vacuum line. Replaced that with narrow vac line and the problem went away.

 

Your video doesn't sound like they're stuck open, hmm. I can hear the turbo and then it is drowned out by the wastegate noise. Btw, do you have a bov on that thing?

 

Did he post a video?

 

YEA, did I??? Nope, not yet, not my vid. I am lookin for the camera right now.