Re: where is your restrictor valve set at?
 

so is it safe to say 1/4 open would be ok for the turbo?

Re: where is your restrictor valve set at?
 

it would be safer to adjust with your oil pressure gauge ;)

Re: where is your restrictor valve set at?
 

best with an oil pressure gauge.

Most people use them to avoid smoking, in that case go with the most oil you can without getting the white smoke.