ok i have searched for a fourm on this subject and couldnt find what i was lookin for.
I have a bad screeching noise coming from the belt area of my car when it is cold outside or when my ac is on and when my rpms hit 4000 on a blitz super charged engine. does anyone know the problem and how to fix it? your help will be greatly apreciated thanks

it could be your alternator belt....
i used to have a problem like that with my OLD rav-4 ( 98 )
everytime i turned the ac on a high pitch screeching sound happens...
so i checked my belts and my alternator was all crap...
it was old and needed a change...

so then i changed it (cost me less than 100 bucks, not sure on the xb)
and it solved my probelm....

hope this helps man...Good Luck

Wait, are you supercharged? If so what pulley are you running.

I had this same problem in my tC, where the mechanism that adjusts the tension on the belt cant handle smaller pullys and it squeals for some reason.

IDK Just my suggestions.

No real tensioner on the xB Classic, but if the belt is not tightened to spec it WILL squeal under load, ESPECIALLY when cold.

Pretty common - Adjust belt tension before you damage the belt.

(Or replace belt of it is old enough to be questionable.)

tomas nails it agian.
thats my vote, eather your belt is bad or loose