Just installed it, love the sound and the perceived gains...

But between 3-4k rpms, I get a pronounced high pitched whistle. It is not the typical sound of the intake sucking in more air...but actually a whistle type sound.

Anyone else have this, and is this normal?

 

yes its normal... please look at the other 9000 threads on the pop charger's hissing sound.

 

Yup its the sound you get with any intake of the MAF opening and closing.

 

Thanks for the response/confirmation guys! I woulda done a search..but apparently that function hasn't been working for a few weeks it seems...