Odd boost taper
 

Recently installed a JDL turbo kit. The tial wastegate has the 8.5 psi spring with no boost control. However during ecutek street tuning boost would only hit 7.x psi and then taper to 4.x psi up top.

Any ideas? Visually everything looks ok. I would assume a massive boost leak would be probable or a wastegate malfunction which I'm sure is rare.

Another odd thing is the car runs and idles fine otherwise. So the leak must be far from the MAF??

malfunctioning BOV ?

I'd suggest to check for vacuum boost / leaks 1st and also check that the throttle is fully open