Originally Posted by SLK32Germany

Keep in mind that boost is depending very much on the outside temperature... I have a pulley ratio of 2,5 (like the 185mm Pulley).

At 33 degrees C I got 17,3 PSI of boost and when its cold (10 degrees C) I got 20,6 PSI.

Also the exhaust affects the boost, the less restriction is in the exhaust(only 2 Cats, bigger exhaust manifolds) the less boost you get...