Seems like when i take 1st gear to like 5000,5500RPM and i let the car come down..theres kinda like a whistling noise..it seems to go away and no performance feels like its lost..but its a weird whistling noise that lasts like 5-10 seconds..should i be worried?

 

It's probably from the FIPK. I know mine lid has alot more intake noise then the stock, so I can just imagine what the FIPK sounds like.

 

i thought the same thing..but it was doing it at idle. Then when i took off again..it went away..

I had the LS6 intake recently done..could that do it somehow?