I think this is a great experiment... looking forward to the pictures. Would I go to all this particular extra effort in this one area myself... probably not. Gonna enjoy learning from someone else's experience ? Absolutely !!The after-run cool down cycle is pretty standard as a way to deal with heat soak... given how self-contained you are building this system you could easily add a simple timer circuit to run your oil cooling system for a few minutes after you shut down the engine. Or close the loop completely and have the after-run cooling cycle temperature controlled ?? Sounds like you have an oil temperature sensor in place already ?
I'm interested to see your setup, and understand your logic, so I'm not interested in bashing As promised. Please find below a picture of the components of my turbo independent lubrication system.From left to right:1) a home built independent oil can. This is a steel box approximately 6" x6" x6". Inside I have set a baffle so that the oil return will not be interfered with . The whole idea about this item is that oil should be allowed to drain down from the turbo with no obstacle. This is the logic of the stock VW discharge (to the oil pan) and I have stuck to it. On my system the oil is being discharged through a 3/8" hydraulic hose crimped at both ends. The fill cap is also a vent. I bought it (cheap) at Princess Auto, it is a product used on hydraulic tanks. Note that the can will be filled only up to 2/3 of its height to allow for oil expansion and bucket effect. The total oil volume is then 1200 cc. 2) The oil pump is a 12 volt pump bought at Summit Racing. It is a positive displacement piston/diaphragm type of pump designed for continuous use.3) Oil filter and filter head 1/2" NPT bought at Princess Auto in the same department. I made the stand.4) A small oil radiator Rapid-Cool from NAPA. It will be straped to the main (water)radiator.5) Home made Oil temperature/oil pressure switch. This unit will send a panick signal to two red lights when needed.Next these will be plumbed permanently in my car. The actual setting may be of limited interest to you since my car is not a VW but a homebuilt sportscar with a longitudinal engine and Suzuki transmission. This means that a good deal of features have be modified to meet this car. If any one is interested I will show pictures later.Testing of this lubrication system will not be done until May/June when I finally roll the car out.I am available for more details if I can be of use.Haybayian.
Why not run a oil/water core? Some garretts are dual cooled. My IHI 5RHB in my old Thunderbird TurboCoupe was that. Far simpler, just need to run a tap off the coolant line to and from the turbo.
Does the flowrate of oil to the turbo need to be varied according to the speed of the turbine? I'm thinking at engine idle when turbine is barely rotating will the excessive oil squirt out of bearings and into intake or exhaust? Or is this wrong thinking and the bearings free draining?