I will try to go as soft as I can on the stiffer spring. Also will take a look for the soft spring but I did purchase this in 06' so I may not have it. It was most likely operating like this prior to now but I could not hear it. It was changed to the harder spring and set up at Turbo Trix during a tune. It doesn't seem to be operating correctly. If need be the new Tial QRJ would be an option.

 

I ran it set to at its softest on the stiffer spring and still the same thing just with more flutter.

 

To be clear is there a dedicated line to the valve. Can you take a pic of your engine bay? I've had my type s with various cam and turbo combinations with no issues. I don't think your valve is really any different