sts turbo ??
I DO NOT have an oil restrictor in the feed line, I have a NON-KINKED and STRAIGHT to slightly curved oil return line to the oil pan with a Turbowerx Exa Pump. i'm not seeing a damn thing but clean pipes.
Unless you are above 70 or so oil feed PSI you do not need a restrictor in the oil feed line to the turbo, Providing you have a good return line for your application.


