It seems that this is common with rebuilt turbos. Nothing close to factory settings, but also they cost a third part of a new one.
Today I did another 1/2 turn to the stop screw, now the boost comes nearly at 2100rpm and also the engine holds on light hills in 5th gear at 1900-2000rpm.
I also noticed that it no longer smokes under hard acceleration. Before, it did a very niceable fog when driving at night with a car behind you.
Today I did some crazy accelerations to ensure there was no boost errors and the turbo was holding well, and I saw nothing smokey behind.
All seems to be getting better. Slowly, but better
As a fun fact, after adjusting the stop screw and tightening the nut, half of the tool came loose and fell into the sump cover, behind the downpipe, and completely inaccessible.
It was already night and had to go home! I tried to push the accelerator and the brakes several times, quickly to shake the car and move the part, but did nothing.
I gave up, but and an hour later something hitted the car's floor. We turned back and after 10 minutes of searching, the tool was in the middle of the road. Gotcha!
If anything tighten the screw, I have never messed with it personally. The VNT can be moved but it should be left to a pro if you don't fully understand boost targets, etc.
Of course, a pro knows what to do. But in this case, the stop screw was proven to be the problem.
Out of the box, the turbo boost was coming at 2700rpm . +1 turn and came at 2500. +1 and 2300. +1/2 and 2100. It's getting close!
And the screw is just a bit over it's half, so I guess there's still a lot of screw to play with.