how many pounds of boost is a stock 02 mcs runing from factory. the new pulley ( which will be here on thursday) says a 4 psi increase. i just wanted to figure out what kind of boost psi ill be running

 

From what I've read, stock is supposedly 10 to 10.5 psi, just an intake is rumored to increase boost by 1 to 1.5 psi because the stock airbox is so restrictive, and the 15% pulley is supposed to increase it around 4 psi... this is of course assuming that all of your seals are tight.

I've seen a max of about 14.5 to 15 psi with a 15% reduction pulley & steel-mesh cone..