This thread is for every guy who has ever blown a turbo, only to find oil in the intake pipes. First of all, and most importantly, the oil drain line. In this case, size DOES matter. I blew oil past the turbo's seals multiple times when I had the STS oil drain setup and I have had no issues since I incorporated this drain setup with AN-10 line. The point of having the big drain line is to use gravity to allow the oil to drain freely, and without restriction, out of the center section. This prevents the oil from pooling up in the center section and pushing past the seals. A 90* fitting on the drain may not be the best idea, but notice how I allowed 4" of pipe from the center section as to allow the oil to pool up in the line underneath the turbo, rather than inside the turbo - then the pump takes over. BTW, only use the ExaPump for oil scavenging because it is quite simply the BEST pump for oil scavenging, period.
Second, is the oil restrictor. Most people do not understand how common over-oiling a turbo is. STS seems to think that a wide-open AN-4 line, without a restrictor, and with about 60psi of oil pressure @ WOT will not harm the turbo - Those idiots are WRONG. Most turbos need an oil restrictor and the size of which will vary from turbo to turbo. For example, I run a journal bearing 60mm and I use a 0.065" restrictor which is a tad big for that turbo though - a 0.050" would probably be better. Notice in the picture how the restrictor is mounted prior to the 90* fitting. This allows the restricted oil to hit the side wall of the 90* fitting, then trickle down into the center section thus providing a gentle flow of oil. If you install the restrictor directly into the center section, you will have a pressurized jet violently spraying the center section with oil which I think could be bad.
Last, but still important, the PCV setup. Like an idiot, I believed the STS PCV setup was sufficient at first. I then realized it chokes the crankcase trying to vent it through one tiny orifice. I also tried putting filters on the valve covers, but I found oil was making its way out the filters and on top of the valve covers - no bueno. Finally, I installed a moroso breather tank. It is a very simple installation and setup which works very well - crankcase doesn't choke @ WOT, valve covers don't get saturated with oil, etc. If the crankcase gets choked @ WOT, your oil pressure will skyrocket and the turbo will probably give. Installation is simple - just mount the tank and run hoses from it to the valve cover nipples.