What's so bad about that?

[Richard]

Would be the problem with swapping the waste gate oil line and the turbo oil feed line? You would have better volume on an admittedly poor oil supply to the turbo and filtered oil to the waste gate. Have I got it wrong?

[Kevin McDole]

Richard,

Maybe I'm misunderstanding your question, but here goes ...

The turbo system is a closed loop consisting of the controller, waste gate, and turbo. The controller senses the upper deck pressure and positions the waste gate using oil pressure.

If you swap those lines, then you will get some "random" waste gate position based on the turbo line oil pressure - and the turbo will not receive the correct oil flow, but rather some "random" supply based on the upper deck pressure.

In summary, your turbo system won't work correctly, and this very well may destroy the turbo - if not the entire engine (with an overboost).

[Richard]

I think I've got the question confused then, or maybe I'm confused. You have one oil line on the bottom the of the sump. This comes right after the oil pump and before the oil filter. This line supplies unfiltered oil to the waste gate which is controlled by the bellows on the controller and returned to sump.

The turbo line comes after the filter, from the oil galley on the side of the engine. From there into the turbo and back to sump via the scaveng pump. Thus two completely different systems.

There has been debate on the unfiltered oil that comes from the wastegate supply side. And other studies that depict the oil supply for the turbo as a poor choice for volume sake.

So, if you supplied the turbo from the lower sump, and the wastegate by the oil galley. The oil pressure is the same at either point on the engine.

I'm just trying to understand the system. Maybe I have it all wrong. Someone please correct me if I am.