so at no point have you changed the oil and filter ?
how much oil is in it ? [i know you will read this, an yeah i was thinkin of you !]
the turbo has been buillt by someone proper hasnt it, or is it an ebay diy kit ?
off top of my head thats some good oil pressure, i have tried a few things an i dont think im anywhere near that. if i remember i'll have a look in my notes but i recon there maybe something there
i have used restrictors in oil lines, for a journal bearing turbo i dont advise it