So I recently bought TII with FMIC and Greddy BOV. I'm new to owning a boosted car so I haven't tried messing with anything yet.

I noticed this weird sound in 2 different situations.

First one is sometimes after I shift and the BOV makes its normal sound I hear a eeeee rrrrrrr noise O.O Almost sounds like metal rubbing for a second or a bird call.

It also makes this sound if I barely get into boost like 1- 3psi and instead of making the normal BOV sound it just makes that weird noise.

It's not a flutter like the spring is set too hard in the BOV.

Could it possibly be set just a little too soft?

 

could be a little soft. let off the gas under boost its gonna make a noise. if its making noise under boost tighten the nut on top one half turn at a time untill it stops/

 

I would take it apart and clean it, or yes it may be set too soft.