Just wondering when full boost should kit in on a stock sr20 with 3 inch exhaust all
the way back. It used to kick in around 2800 rpms, now I hear a bad rattle sound like an open exhaust manifold. Boost takes a lot longer at 3700 rpms. I cant tell if its an exhaust leak or the turbo is blown.

My friends stock sr kicks in about 24XX ~25XX. 3700 is pretty high for a stock t25. I would check for exaust leaks... Prob. a riped gasket

yeah i check it the next day when my car was cold. the turbo inlet gasket is blown