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Oil restrictor plate for turbos

journal bearing.

Ok, thanks. I ask because I am running a 4an line from my oil sender port to feed the turbo with no restrictor. When the car is under boost and the oil pressure is over 60 psi, I get some oil-smoke out the exhaust. I am wondering if there is too much oil in the turbo, or if the seals are going bad.
 
So do most...if not all Garrett BB GT series turbos IIRC. There's one built into/threaded into the body of my GT35R.

Not on my GT30R, there isn't. I forgot to install a restrictor once after removing turbo for some reason and then when it was all back together it was pushing oil past the seals into both the compressor and turbine.
 
Not on my GT30R, there isn't. I forgot to install a restrictor once after removing turbo for some reason and then when it was all back together it was pushing oil past the seals into both the compressor and turbine.
If you look down into the oil feed hole on mine...you can see something that's been threaded down into the feed hole. It's a resrtictor that sits deep...almost at the CHRA...but it doesn't have a tiny feed hole...it's rather large actually. Not much of a step down from the actual threads themselves. I'd take a pic to show but it's bolted to my motor right now.
 
...If say you're making on an average 80-100 psi oil pressure you definitely wanna run a restrictor so the seals stay happy....

the "seals" in turbos consist of, usually in our case, a carbon seal up front that prevents the intake vacuum from pulling oil mist into the intake, and a piston ring seal in the back the prevents exhaust gas from pressurizing the crankcase. That's what the seals do. They do not hold any oil pressure. Oil pressure inside the center section is 0 psi. Oil pressurizes the bearings at engine oil pressure, and once it squirts past the bearings, it collect in the center section and drains via gravity out the bottom.

If standard or raised oil pressure results in oil being pumped out the back of the turbo, it means your oil drain is insufficient, or your bearings are so badly worn that the bearing gap is very large which requires a huge amount of volume to maintain pressure, and again, this overwhelms the drain capacity of the oil drain. A oil restrictor on a journal bearing turbo is usually a kludge--people use them when their badly designed or broken turbo oiling system is pumping oil out of the center section, notice the blue smoke goes away, and think they've fixed it. They've simply reduced oil flow through the turbo by starving the bearings. Not like sound logic will stop anyone from pointing out that running no restrictor results in lots of blue smoke and hoo-boy thats a blown turbo!
 
My turbo is a ball bearing unit from innovative and it has a restriction built into it. There is no insert, the feed hole is just drilled very small.
 
Here's my 35R's oil feed...you can kinda see the top of it in the 1st pic
turborestrictor001.jpg

turborestrictor002.jpg

I can't believe I fit my camera in there
 
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