I got the fuel pump and dynoflash a couple of weeks ago. the car is running very smooth till red line(thanks to big Al!).

however, i started to hear high-pitch whinning noise.

with the music on and high speed driving, i can't hardly notice however, with music off and waiting on the signal, i can hear it very clearly.
it's coming rear passenger side! not from where fuel pump is located.

is it serious?? it really bothers me.

 

if its a walboro pump, its the pump. Mine makes the same noise but you get used to it after about a week. Hell with my greddy Ti I hardly hear it.

 

take your back seat out (bottom part) , then drive it, see if its even louder, its a loud pump