oil pressure for turbo

#1
Question I have is how much oil pressure is needed for the turbo ?

I think a non-ball bearing would need more to keep the shaft lubricated.

Has anyone put either a regulator or restrictor in the "in" side of the turbo oil side ?
 
#2
When you buy a BB turbo you typically get a fitting with a restrictor built in.
JB typical can handle 100psi or more from what I can tell. Bison or someone else that knows turbos in and out be give you more of a detailed answer. I do know you need to have the return flow back without issues or it will push out of the seal.
 
#4
I was wondering because my turbo was leaking oil into the intake side so I sent it to Turbonetics to be rebuilt.

Got the report back that the center section was bad and needed to be replaced along with the bearings.I

It has been rebuilt , but wonder if I need to limit the oil pressure so not to damage anything with the "new" turbo.
 

bison

Moderator
Staff member
#5
When you buy a BB turbo you typically get a fitting with a restrictor built in.
JB typical can handle 100psi or more from what I can tell. Bison or someone else that knows turbos in and out be give you more of a detailed answer. I do know you need to have the return flow back without issues or it will push out of the seal.
There aren’t any seals in turbos unless they have a carbon faced seal on the compressor side which is not typical of high performance turbos especially when there’s no vacuum subjected to the inlet side. There’s just two rings like piston rings that have tension against the round ring bores in the bearing housing and backplate. They stop cross talk between the crankcase and exhaust and crankcase and air inlet. They are not positive seals and won’t seal pressure at all. They are more of a barrier. I prefer to use stepped gap rings on the exhaust side to minimize the ring gap on everything i sell. The most oil control occurs from gravity and slinging. The rings can minimize anything that gets into the bore area but absolutely will not 100% seal. The biggest problems occur from drain back problems and higher crankcase pressure on immediate declaration. The oil leaks past the rings at that time.


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#6
I was wondering because my turbo was leaking oil into the intake side so I sent it to Turbonetics to be rebuilt.

Got the report back that the center section was bad and needed to be replaced along with the bearings replaced.

Maybe it will fix the leaking oil issue, but wonder if I need to limit the oil pressure so not to damage anything with the "new" turbo.
Did the report suggest why the center section failed, and do you know what oil pressures you were experiencing when it failed?

You're guessing without data. Stop that. You'll just end up setting money on fire.
 

bison

Moderator
Staff member
#7
I was wondering because my turbo was leaking oil into the intake side so I sent it to Turbonetics to be rebuilt.

Got the report back that the center section was bad and needed to be replaced along with the bearings.I

It has been rebuilt , but wonder if I need to limit the oil pressure so not to damage anything with the "new" turbo.
It’s possible the bearing to shaft and bore clearances were out of spec and caused excessive oil leakage like having too loose oil clearances in an engine and it throws a bunch of oil into the windage and up on the cylinder walls


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#8
Did the report suggest why the center section failed, and do you know what oil pressures you were experiencing when it failed?

You're guessing without data. Stop that. You'll just end up setting money on fire.
Not sure why it did what it did. Just wondering what I can do so it will not happen again.

I have a remote filter before so the oil gets filtered before it goes the turbo.

He said one of the bearing scored (locked up) and cracked the center section. The center section needed to be replaced.

It is on it's way back now and it will be like new when I get it.
 
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hensleyt

Active Member
#9
TurboSmart makes a oil pressure regular. I had considered one at one time my oil pressure is 75@5500 rpm, but with no restrictions on the return side I don’t believe the oil pressure inside the center section to be very high,this is probably why there no real seal just the pistion ring on the shaft.
Just think about it every time you install the turbo and don’t get the return tub sealed it just drips oil doesn’t spray all over.
 

TurboBuRick

Moderator
Staff member
#10
Not sure why it did what it did. Just wondering what I can do so it will not happen again.

I have a remote filter before so the oil gets filtered before it goes the turbo.
PTE Turbo Saver? Or?

Just a little food for thought. If using PTE remote filter, double check IN and OUT ports configuration.

OUT of adapter flange goes to IN on the remote filter

OUT of the remote filter goes to IN on the adapter flange

I've seen this wrong on more than one car
 
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#11
Remote Turbo oil/saver was on the car when I bought it. I have changed the filter a few times but it it up behind the passenger's headlights.

The parts that Turbonetics sent me back only had one "seal" so I don't know if the is it.
 

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#12
TurboSmart makes a oil pressure regular. I had considered one at one time my oil pressure is 75@5500 rpm, but with no restrictions on the return side I don’t believe the oil pressure inside the center section to be very high,this is probably why there no real seal just the pistion ring on the shaft.
Just think about it every time you install the turbo and don’t get the return tub sealed it just drips oil doesn’t spray all over.

I am going to take the GN1 return off and make the 45 degree a 35 degree as it had a little kink in it.

Should the 45 bend or the 90 bend be at the turbo ?
 

RUQWKNF

KEEPER OF SECRETS
Staff member
#15
I would not put that oil drain back on the car. Oil will back up big time. One thing people need to know, the oil that comes out of the turbo is not a nice flow like a water faucet. It is an aerated mess. This is why the factory drain tube has convolutes, to help the oil collect and drain back in to the valley. I have yet to see an aftermarket SS braided drain that 100% eliminates the kink. Also, you'll note, the stock drain tube doesn't have a direct 90* at the block. But rather a smooth transition out of the turbo and into the block. (see image below) This is critical. The ID of the drain is also critical. Journal bearing turbos can typically take 80psi before showing signs of leakage aka before oil gets by the oil ring on the exhaust side. DBB turbos with the internal restrictor such as the air cooled DBB chra from PTE can take more, but we always recommended keeping oil pressure below 80psi to be on the safe side. Bison is correct, there are no 100% sealed oil seals in either style turbo, but the dbb is a little bit more resilient due to the contained cartridge, vs a jb chra.



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As far as controlling the amount of oil to the turbo, I would not put a restrictor on either style turbo. Doing so will shorten the life of the chra.

If this is a jb turbo, there are two things that can prolong the life. (if you have filtered oil feeding the turbo already)

1. Slowly lift off the throttle when getting off the gas from WOT, vs slamming the throttle shut.
2. Have the turbo retrofitted with a Ported Shroud S style compressor cover, to help keep it from surging under half throttle and most importantly, to help keep the rotating assembly from spinning 110k rpm one direction, then immediately reversing and spinning 110k RPM the other direction when you get off the gas. Or, install a blow off valve, but that is not typical. Without those two, on a jb turbo, you will eventually "knock the thrust" out of the jb bearing system. When this happens, the oil seal, really an oil control ring (piston ring as mentioned earlier) get's taken out and the thrust bearing is next to go along with the actual bushings. When you have signs of oil in the compressor cover, or the compressor wheel rubbing the compressor cover, the thrust is gone and it's toast. Running a turbo with the thrust knocked out or compressor wheel rubbing the cover is only blowing metal into the engine and contaminating the oil with further metal particles.

I highly recommend, always running a ported shroud S compressor cover on any journal bearing turbo going on a street driven Turbo Buick. I also highly recommend the factory style oil drain tube, if cracked, replace it with an OEM tube. And having filtered oil with ZDDPlus to the turbo at all times.

-Patrick-
 

Mr.Spool

Well-Known Member
#16
t has been rebuilt , but wonder if I need to limit the oil pressure so not to damage anything with the "new" turbo.
i have run a several different turbonetics bb units over the years,never changed or adjusted anything and i have lets just say alot of oil pressure in my built 109.only damage i have seen is from overspeeding the turbo.not sure it helps but i use synthetic motor oil
 
#17
It is a DBB, have a blow off valve and now wish I would have kept the factory drain back line.

This past summer's (had 20w-50 synthetic Mobil) oil was a little thick so I am going to drop the weight some so the cold pressure is not 80 PSI