My curiosity has brought me accross a manual boost controller. I got it for free and set it up the other weekend. I also bought a cheapo vacuum/psi guage to determine how much boost the turbo was putting out. Of course, I started out with the adjustment screw all the way out so the turbo would still be putting out stock psi.
From my knowledge I thought that volvo had set up the turbo to run at 8 psi full boost. By the way this is an 89' 740 b230ft with a garett turbo. After hooking up the cheapo guage to the line coming off the intake hose to the stock turbo guage, it read 4 psi at full boost. Of course, there is boost seepage for a second right away when the wastegate cannot keep up, but then it returns back to 4 psi with the pedal still on the floor.
I started to slowly turn the adjustment screw in, eventually reaching 5.5 psi with boost seepage pegging 9.5-10 psi.
I am afraid to go any further until I get some input on this. First, does the wastegate always play catch-up and allow that much boost before opening? Also, assuming the turbo hasn't been tampered with, could 4 psi be the stock setting or could my cheapo guage be way off? I do not care about the turbo itself, it can handle it, but I know I don't have the big rods, so I want to be careful.

Any and all insight, information would be greatly appreciated.

Thanks in advance,

Brant