Best location of turbo oil drain in sump

[stidnam]

Looking at my sump which I will have to add a turbo oil drain to I was wondering what was the best spot for this.

Here is the sump


The red line is the oil level when the oil is at the full mark on the dipstick. The red circle is the drain return on the trust lower sump piece that I have just gotten (not pictured) which is lower than the full oil level. The blue circle is where I think it is best to go as it is above the full oil level.

So is there any disadvantages to using the return in the trust sump (red circle) considering it is already tapped and all I'd need to do is screw in a fitting. Its not ideal but surely it can't grenade the turbo or else the trust people wouldn't have designed it with the fitting in the sump.

Thoughts anyone?

[jeffro ra28]

I think your spot on the money with your blue circle

[TurboRA28]

Yeah i've not seen an oil drain lower than the oil level? I'd put it above oil level..

[thechuckster]

turbo oil drain has to free flow - make sure it meets the sump above the full-oil level.

[Billzilla]

As above, and make sure the return in on the side of the engine that has the crank going downwards as it swings past the side of the sump, to help the oil escape.

[mullett]

Yup, done this before by filling a car while it was still on stands (and thus at an angle). If the oil level is above the drain, the oil backs up and blows the seals out of your turbo, making your car smoke like gods gift to the hippies.

-RM

[TTCorona]

Yeah my mate did the same think with making an oil drain in his SR20

Definitely needs to be above the oil level, I'd say also by as much as you can to...
remember that depending on the baffles in your sump, the oil moves around a bit when you go around corners etc.

[stidnam]

I can't really put it any higher than the blue circle or else I'll run out of sump material as that position is very close to the mating surface on the bottom of the block. Also have to dodge the bolt hole on the inside of the sump so it can only really go there.

So now that I am definitely going to go with the blue circle, why would the trust people make an oil drain below the full oil level? This is an altezza sump btw so I'd be interested to see whether or not altezza owners with turbos have used this oil return location and experienced problems.

[thechuckster]

are you sure that red fitting is a turbo drain? could be an oil-temp/level sensor port?

you need the turbo oil-drain free flowing - the stuff coming out of the housing is a very hot, oily, frothy, shit that HAS to see crank-case atmosphere not a liquid 'wall', otherwise it'll rapidly pressurise the turbo bearing housing resulting in failed bearings/seals and a smoke trail like a VL-single-legger.

[jeffro ra28]

To split hairs it is also advised that the oil drain face the back of the sump. As the oil will naturally want to flow towards the back under acceleration etc.

[stidnam]

Yep sure the red circle is the trust oil return fitting.

Quote of engrish
"As the one for oil return of GReddy turbo KIT and the like, the GReddy hose union
　In order to be able to install the 16φL type 90°, 1/2PT is provided."

[thechuckster]

engrish repry: is retarded fitting sump return of oil location. Greddy sticker applied door to is for 20kw gain of horsepowerage.

[Shifty]

Personally I would feed the oil back to the end of the shallow part of the sump, this will allow the oil to run down and give a chance for any aeration to dissipate before it rejoins the oil pan itself.