How is your turbo sump/collector vented ?

I have run several turbo's low mount, current one uses a piece of 40x40mm square tube about 120mm long that bolts to the bottom of turbo oil drain(crush tubes in bolt holes).... that is all the sump that is required. The square tube has a -6 fitting welded in bottom corner that the scavenge pump sucks on and a -6 vent in the top that is plumbed to catch can, pretty much atmo.

Have run garrett and precision turbo's like this with no restrictor.

What is the issue you are having ?

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MY99 WRX EJ2.35L 720whp 9.48@147mph
https://youtu.be/c_lYEG0_Dyo

Right now i dont think there is an issue. But i havent properly driven on it yet. Only idling and free-revving in the garage. I want it to work 100% right when the car is driven and raced again. and that is why i rebuilt the sump. I am trying to do everything i can in order to anticipate potential problems and improve things as best as i can.

Initially i had it backing up oil. And i did also have a small amount of oil in the exhaust and intercooler piping that overflowed from a oil filled core. But i think that was 2 problems i have now already fixed. 1st was do to with the accusump discharging (solenoid was leaking back after shutdown with the scavenge pump off) and also not giving the scavenge pump enough time to clear oil before/after running. Which i am pretty confident was what led to the overfill and oil past the seals. So a leak-free solenoid was fitted, and i have the pump active for 30secs after engine shutdown.

I did also go from a 1mm restrictor down to a slightly smaller 0.035" restrictor. As potential trouble shooting. 1mm is approx 0.040". From my research, 1mm and 0.035" are both common sizes to use on BB Garrett cores. Garrett specify a max of 45psi oil pressure, hence why a restrictor is used. Journal bearing turbos do not want a restrictor, and they function best at as much oil pressure as you can feed them. But BB turbos supposedly dont need such high pressure, and Garrett even go so far as to say between 40 and 45 psi. Obviously its very difficult to actually measure the pressure drop over the restrictor. So i did some looking around and chose the 0.035" size as a compromise between the probably better 1mm size, and the potential oil clearing issues from a low mount turbo.

The 2nd issue was i dont think i had the turbo core clocked perfectly, and also had too much angle of the rotation axis away from parallel. So i reclocked the core better. And i loosened the V-band turbine inlet and rotated it and got the turbo sitting more hotizontal. Before it had over 15° away from horizontal. Now i have just under 15° away from horizontal. Garrett specify no more than 15° in thier tech section. And with core clocking, i had it so the coolant in was lower than coolant out. But probably a bit too much. Now i have it slightly less. Meaning the drain is closer to vertical.

But since i did all that it was all good. But because i slightly reposititioned my turbo. The first oil collector i built (ss316 round one) was not at a good angle/hieght. And i had been doing research about turbo draining and alot of problems were over come by using larger port directly out of the core. (Ie NOT those AN10 adapters like i was originally using.)

So the potential bottle neck in the 45° AN10 union and drain fitting, plus also the now no longer perfect angle on the stainless steel collector, led me to build a new collector out of aluminium. As seen in that youtube video i just put up. Again, that was more preventing potential problems rather than fixing actual problems. I wanted to be 100% happy with the setup before going in for tuning next year.

Re your question about the venting. The collector is vented to the 2 catch cans. Basically i ran 2 hoses down from the drain fitting on the catch cans directly to the oil collector. 2 reasons. First is to prevent vacuum in the collector from the scavenge pump. The other was to allow the catch cans to self drain oil back to the engine. I welded up the base of the weld fittings for the catchcan drain before i welded them to the tank. Then redrilled the wholes a bit smaller so they arent too free flowing. I actually drilled each one out to 1.5mm. But on the video i daid 1mm by mistake.

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Doing it for all the wagons out there

Wish i had of made my setup so simple. In typical Bram style, i always opt for the most complex over the top solution to any problem. Haha. Anyways, that sounds like effectively the same as what i have but way less complicated. So if that works for you, then i feel pretty good thqt my setup will be adequate.

BTW. What scavenge pump do you run?

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Doing it for all the wagons out there