i see what you're saying. But the turbo is set to build boost to 7 psi then no more. So it would still fill up the larger "garden hose" a little bit slower, but still should built to 7 then stop. The garden hose is a good analogy, but not perfect since the intake tract isnt an open system. Its like having the hose plugged at the end except for a little hole, with the water pressure only being 7psi. I still think he had a bottle neck at the intercooler since he's most likely using one with a few long tubes. The boost gauge is probably at the manifold, so he sees the pressure after the cork.

I went from factory IC pipes and a semi-restrictive factory IC to a VERY high flowing, almost zero pressure drop Spearco IC with very smooth mandrel bent 2.5" IC pipes. I picked UP a few PSI with just that change, and the engine revved MUCH quicker.