Feels like losing power.
 

I was test driving an MK3 Turbo with 3"ex and intake and running 10lbs. As soon as we hit 4100-4200RPM's the car sort of flatlined and then seem to die out around 5200. Before he upd the boost, it felt good throughout all the way to 6000. Obviously a little tired at 6000, but solid. Pulled all the way. Thought it was the plugs and wires, switched them out and still the same. Any thoughts on what it could be?

The power wont be there until redline. 5200 is about where the power peaks.

I guess we are to used to driving hondas.