Make sure the wastegate is sealed to the manifold properly if you are running an external wastegate. The bolts on mine backed out once and wouldn't get me past 3lbs. Also, what are you using to trick the ecu? If you're using a missing link, check the little filter that sits in the side. If your ecu starts seeing positive map, it'll F with the timing and you won't be building much boost, if any.

I CONTRIBUTED TO THE WIKI!
ah... turbo. I love the turbo, the boost, the speed, the sound.
and its all better when you do it yourself. cheaper too.