i can hear the supercharger alot more now and the deeper sound during acceleration but i also hear a high pitch whistle every now again almost high pitch enough to be a dog whistle is this normal?

 

At about 3300 rpm I can sometimes hear a bit of something...but I only had it for a week.....I then did a pulley....and the supercharger whine got a bit more pronounced....now I can't hear anything....unless I try really hard, and even then I am not sure.....
With the Alta's the whistle is Very loud....it has been postulated that we all have the whistle...just some intakes muffle it better than others, or just simply overpower it with supercharger wine.
I think Blimey had a jcw with a loud whistle....tracked it down to the throttle body or something....said it was much worse on a jcw.
Overall I would say get a pulley.....I waited.....and debated.....finely did it....it simply transforms the car. There is some debate on what reduction to use, but with an auto, since you rpm's are generly lower than a stick, the 17% should be safe...it simply amazing....gets rid of the lag you get with the a/c on too.

 

its the supercharger bypass valve. at partial throttle (usually low rpms) the valve is not all the way cosed, but it only partially open, because it does not use the full vacuum to keep it closed( or is it the reverse way.. i cant remember, all i know is installing the DT BPV makes it go away almost completely, or it did for me). it vibrates a bit causing the air to whistle. If you step on it, youl never hear it, cause the valve will close. no more whistle. But yes its normal. The stock intake just muffled it enough so you cannot hear it.

 

well this is good news!