compressor surge with 50 trim?

[GreddySpyder]

I am running an internally gated 50 trim and I get what seems to be compressor surge sometimes. When I let off the gas at lower boost levels the BOV makes one clean "whistle" noise, but when I am going full throttle and shift I hear a "whistle, cha, cha" kind of noise, almost like a bov sound mixed with what i think is the sound of compressor surge. I have tried adjusting the bov, could it possibly be that the wastegate arm needs adjusting, or is there anything else to try?

 

[jdmawd]

At what boost level and are you sure you were WOT. I only ask because I noticed the same effect if the turbo spools but im only at part throttle. but my boost level was around 25 psi.

I initially thought it was the BOV fluttering under high boost(pos RFL). I later realized that the turbo was spooling but I did not have the throttle plate completely open. i only get that little cha cha cha at high boost levels at part throttle.

 

[44pirate]

I have the same thing. Adjusting the Type S is a PITA. I worry about the compressor surge at WOT more than at low boost level.