I am running a 4.5# pulley and want to increase to 6#. Any benifits/dangers to just buying something more like a 9# and using a bypass or blow off valve to drop back down to 6#? Im thinking more boost quicker is better as long as u are not running to much to fastat low rpms?
94 ta
powerdyne 4.5

 

I think what you're asking is can you use a 9# pulley to make boost quicker, but have something to bleed off pressure so it never exceeds 6psi. If this is what you're asking, the answer is no, you can't. Sorry.

 

It doesn't work like that. The bypass/BOV is not meant to limit boost to a particular amount. The bypass is designed to be open at idle and light to mid throttle, venting the extra air put out by the blower, not needed in those conditions.
The bypass and bov both are used to vent the extra air when you come off the boost, and the throttle blades slam shut, so the air has somewhere to go, instead of back to the compressor.

They in no way are intended to open at a specific # of boost.