- Aug 10, 2004
It sounds like your trying to avoid modifying your oil pan. You can run a -20AN line but the hole in the oil pan is still to small to drain two turbos. Oil pan modification is going to have to happen. I wouldn't take any short cuts when it comes to a compound setup. Do it once and do it right with each turbo having its own drain. Those are my thoughts on it atleast.
I agree with the "do it once, do it right" idea, however just because one person does something one way doesn't mean that a different way a person accomplishes the same task "isn't right." I have done a few things to my DSM for which I was laughed at and told it wasn't the "right" way to do it and here I am a few thousand miles later running 30+psi on a 65lb/min turbo with no issues as a result of me doing it the way someone else said was "the wrong way."
I agree with you though that 10an may be a bit small, but instead of messing with welding fittings on my current oil pan, I did see a pan with one -12an fitting already welded on for sale which would make things much easier for me than taking my pan off, buying 2 fittings, then taking them 10mi away to the welder and having to pay him to weld them on, then pick it up, bring it back, and puit it back on the car. If I bought a pan with one -12an fitting already welded on, I simply pull one pan off, put the next pan on, and away I go. I want to do it in a manner that is functional and requires the least amount of labor/money possible.
I run my 50 trim and S475 into a 5/8th plastic Tee, which then goes to the pan. The Tee is at the level of the pan fitting. In fact, ,the 50 trim is level with the pan fitting, so that whole damn thing is all horizontal, only the leg going to the 475 is vertical. None of this should work. But it does.
With a BB turbos that uses very little oil and an MHI, Garrett, BW, or any other OEM or OEM based turbo, I would try it. PTE turbos are the only ones I've used that try to burn the car down if the drain line isn't completely vertical all the way to the pan. The seal system they use is very sesnsitive to oil backing up in the drain even slightly. OEM turbos are pretty tolerant.
That being said, I've been meaning to cut off the existing 5/8ths stub on the oil pan and weld on 2 10an fittings since I built this setup in 2009. There hasn't been a pressing need, other than cleaning it up a little, so I keep putting it off.
Yeah, MHI and Garrett are the turbos in question. I probably wouldn't try this with a Holset based on what I have read. The other thing I am wondering if it would help in running one line, I have a crank evac system like Paul's, so would a system like that creating vacuum in the crank case help pull the oil into the pan as opposed to relying on just gravity to get it from the turbo to the pan?