what oil pressure to turbo?

i put a oil pressure gauge and a valve on the feed line to try to lower the pressure. my car runs 25-60 psi when its cold 60 psi. hot 25 or 30 psi. at wot 60 psi. this is to much for the turbo from what i have read but i cant find anything to tell me what pressure to have feeding the turbo. i would think that 15 psi should be enough.
OH THANKS i found it after doing a search and looking at 80 threads. lol
I read 35 psi hope this is right.
I resently developed some smoking at wot,and want to get oil pressure under control before i spend the money on a bigger or a new turbo.
I put new 60# injectors and tt chip and while i was installing i found oil on my plate under the throttle body.
Do you still have the stock turbo and the breather connection from the ps side valve cover to the turbo? You can put a breather in the valve cover and cap the connection on the turbo because this is a source of oil getting into the intake.

I wouldn't restrict oil to a non-BB turbo since it's using oil for cooling and lubrication.