I have a 2009 Lancer Ralliart and I just installed a cobb boost control solenoid as well as an turbo smart Kompact plum black recirculating blow off valve. I stage 2 tuned it using my accessport and took it for a drive to see how it sounded. I noticed as I start reaching peak boost I hear a whistle noise around 2500-3500rpm and it wains off around 4000 when I shift. I checked all my fittings and connections and they all seem fine. I replaced all the stock boost control hose. Also the hose that recirculates for the blow off valve has suction. I'm not sure what it could be and to make matters worse I can't put my stock blow off valve back on to check as I accidentally broke it when taking it off. Any help is much appreciated.

I added an audio file of the noise.

 

I solved the issue! I took a look back at the instructions and realized I had two hoses mixed up on the boost control solenoid and that was causing the sound (oops). Now everything is working as it should thanks for all the people that took a look at this thread.