When im in the higher rpms UNDERBOOST the car will make this noise almost like a really high pitched BOV. It only happens after about 5lbs of boost. Its weird. Sounds almost like a whistle. I replaced the stock BPV and retightend all the intake piping. Anyone have any ideas of what else it could be?

 

its just your s/c whine that whine is normal

 

No its only for a split second. Not supercharger whine. Ever heard a SRT-4 BOV? Sounds like that.

 

its belt slip...i had the same crap happen. Sounds like a shreeking noise right?

 

Yep. My digital boost gauge holds steady though......So i can keep beating on it rite? Im putting my 9.5 pulley back on tomorrow anyhow. Its a toyota belt on the car BTWs.

 

yea, u can beat on it still haha. Your boost gauge probly wont read the slip quick enough and thats why it doesnt show a dip in psi while the belt slips quickly. I had the problem after I took my 9.5 psi pulley off and squeezed the stock pulley in with the 9.5 psi belt...stretched it right out after a couple of months and it started making the same noises you described.

 

Oh word. That makes sense. My regular analog boost gauge (Yeah im a ricer i have 2) starts going ape ____ when it happens and the needle starts jumping around like crazy. Welp thats neat.

 

yup, your good, just change your belt out and you will be back to normal. My belt was slipping so badly that it got to the point where it was constantly making a whine almost like it had straight cut gears in the supercharger or it coulda been mistaken for the sound of a turbo spooling up. It was loud and sounded cool, but it aint cool when your losing power due to belt slip