Does the stock turbo hold its boost all the way until redline or does it taper off after a certain rpm? I ask because around 6 thousand RPM’s I start to lose boost. What could the cause be, exhaust to restrictive, to much fuel, intercooler to restrictive (NPR), not enough air getting to the turbo?

 

no *most* stock turbos don't hold solid boost to redline.

I ay most because I have had experience with a couple, one being my 87, that actually did. However through discussion on the forums I found out that I am an expection to the rule.

You're experiencing normal stock turbo operation.