First of all I see you guys understand a lot about Turbos.

I cannot find any info, about how to find out what amount of oil pressure/flow is correct for particular turbo. On google or in other documentation about building turbo systems I always came up with answer that says "See OEM specs." But what if there is no specs for the turbo that I have?!

Do you know any physical test/method, to find out these variables without having OEM specs?

 

Generic specs, 30-40psi, 4an feed for journal bearing 3an feed for ball bearing. 10an drain or larger.

 

Thank you for your reply. OK, my one is journal bearing and I already got -4 feed line. So I should have 30-40psi when engine/oil is hot, yes? under boost or idle?

 

Just an average for the operating range. 15-20psi at warm idle with spikes to 50-60 at wot etc. Cars with higher volume/pressure oil pumps usually need a restrictor if you see more than 50-60psi. I know my car with vct saw 90-100psi cold start and 70-80psi at wot and I had to run a restrictor and even then the seals didn't last more than 3-6 months on my car. After 3 turbo's and numerous rebuilds in 2 years I said screw it and went oil-less turbo best decision I ever made and well worth it.