Oil Restrictors For Turbos On Gtr?

[StockyMcStock]

my GT40 has the oil restrictor built into the cartridge, but it's plain bearing. have you guys heard of plain bearing GT's suffering the same fate you're talking about above? or is it just the ball bearing cores?

also i'm using -6 braided speedflow lines, is there any way your lines can be too big? i'm worried that it will take a while for that volume of space to be filled with oil on start-up that's all. it's high mounted so the oil will probably drain back into the block when the car is turned off

[Mik]

hi i have fitted a few different garret turbo's to rb 26 and most of them will need a restrictor , rb 26 engines have one of the most high oil pressures out of everything i have had instances where engines have been making 50 psi oil pressure at idle , this is to much for a ball bearing turbo turbo at idling speeds and will push oil past the seals and cause it to blow blue smoke at idle ,you need to be using between .9 and 1.1 mm restrictor it does not have to be built into the turbo it can be anywhere in the supply line this will drop your idling pressure to around 10 - 14 psi the oil pressure will increase as the engines revs increase , it would pay to put a oil pressure gauge after the restrictor so you can keep an eye on it

An oil restrictor will increase pressure, not drop it!! It sill restric volume, not pressure! If you mean the pressure in the core itself will drop, then yeah it will.

Edited November 3, 2005 by Mik

[pnblight]

yeah we are trying to drop core pressure on the seals

[djr81]

An oil restrictor will increase pressure, not drop it!! It  sill restric volume, not pressure! If you mean the pressure in the core itself will drop, then yeah it will.

<{POST_SNAPBACK}>

Mik,

Remember that the oil from the oil pump has more than one option - it goes into the motor as well as the turbo. Fitting a flow restrictor on the turbo will not change the pressure upstream worth a damn but will reduce the flow and hence pressure downstream - ie in the bearings and around the seals where it counts.

[R32 TT]

Hey there guys, its seems appropriate to re-open this thread now since I have just taken my car down to the Collie track and guess what?

I think I may have pushed oil past the Turbo seals...

Car went great for just a handful of laps then suddenly lost power.. looked in the rear view mirror to see a large cloud of blue smoke.

This morning, there is a small pool of oil leaking from my BOV's...

Motor seems to run alright though, so hopefully no damage done..

What are people's experiences when this has happened? Just clean out all the intercooler and piping? Fit a restrictor to the turbos and she'll be right? Do the turbo's need to be taken off and looked at?

Or is there something darker awaiting me...

--as a side note--

Oh! I should mention this also. When I got my turbos (they are ball bearing) and spun the compressor wheel on them, they didn't spin for more than about a second. I figured they just needed some oil. Once fitted to the car and they had done some dyno work - I would take the car home and switch it off. If I listened very closely, I could ~just~ hear them spinning down.

Since coming back from the track, you can ~easily~ hear them spinning down - they are MUCH louder.. although my mechanic listened to it and said all the noise just appears to be 'suction' at the pods.. Doesn't sound like bearing noise or anything... Do these things "loosen" up? I am a little worried by the 'change' as I would have thought ball-bearings would be free'd up from day one...

[pnblight]

Hey there guys, its seems appropriate to re-open this thread now since I have just taken my car down to the Collie track and guess what?

I think I may have pushed oil past the Turbo seals...

Car went great for just a handful of laps then suddenly lost power.. looked in the rear view mirror to see a large cloud of blue smoke.

This morning, there is a small pool of oil leaking from my BOV's... 

Motor seems to run alright though, so hopefully no damage done..

What are people's experiences when this has happened?  Just clean out all the intercooler and piping?  Fit a restrictor to the turbos and she'll be right? Do the turbo's need to be taken off and looked at?

Or is there something darker awaiting me...

--as a side note--

Oh! I should mention this also. When I got my turbos (they are ball bearing) and spun the compressor wheel on them, they didn't spin for more than about a second. I figured they just needed some oil. Once fitted to the car and they had done some dyno work - I would take the car home and switch it off. If I listened very closely, I could ~just~ hear them spinning down.

Since coming back from the track, you can ~easily~ hear them spinning down - they are MUCH louder..  although my mechanic listened to it and said all the noise just appears to be 'suction' at the pods..  Doesn't sound like bearing noise or anything...    Do these things "loosen" up? I am a little worried by the 'change' as I would have thought ball-bearings would be free'd up from day one...

<{POST_SNAPBACK}>

This sounds a little different then the normal oil pressure on turbo seals

The engine would have been up to temp by the time you ran into a problem yes?

Are you running std oil pump?

What turbos are you running?

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining) as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

[R31Nismoid]

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining)  as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

thats what im thinking myself

[R32 TT]

This sounds a little different then the normal oil pressure on turbo seals

The engine would have been up to temp by the time you ran into a problem yes?

Are you running std oil pump?

What turbos are you running?

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining)  as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

<{POST_SNAPBACK}>

Hi Pete, yeah I had hoped it was this too. We checked the inside of the pipes from the back rocker cover. They were both 'reasonably dry' although the one on intake side did have a little oil in it.

The thing which made us go to turbo seals was that we popped off the silicon pipe leading off the compressor side of the turbos (the bit that says "twin turbo") and that had oil in it. (quite a bit). So figured this must be it?

Does that sound right?

in answer to your questions though:

Yes the engine was up to temp.

I can only 'assume' the stock internals and oil pump are standard, but can not be sure of what work was done prior (I think its a stock internal job though)

And I am running the 2560r, the -7 though, not the -5 like you.

I didn't fit restrictors because most felt they already had them and Turbotech said I wouldn't need them.. but er.. they might be wrong?

[R31Nismoid]

how much boost and what condition is the motor?

is it a little tired at all?

[R32 TT]

how much boost and what condition is the motor?

is it a little tired at all?

<{POST_SNAPBACK}>

hmm.. I don't think I like where that question is heading...

I refuse to answer that on grounds that it sounds expensive...

...ok, I'll answer. Don't know true km's, but it had 150 across all six when we did a compression check a couple of months back. Haven't done a leak down test though. Might do another test to see if anything has changed.

And it was running about 1.2bar

Now I have had time to think about it - I think its almost certainly oil past the turbo seals since there is oil in pipe coming off the compressor side of the turbo (ie in the piping marked 'twin turbo') . It can't have got in there any other way can it?

And if this is the problem, then the question is: what oil pressure "should" the turbo oil line be restricted to? Has anyone got an actual figure? (that way I can put a gauge on it rather than just picking a size of oil restrictor out of the hat)

[R31Nismoid]

Now I have had time to think about it - I think its almost certainly oil past the turbo seals since there is oil in pipe coming off the compressor side of the turbo (ie in the piping marked 'twin turbo') . It can't have got in there any other way can it?

blowby, thats the usual one. if the rear seal is gone then it wont have oil in the intake side

sounds like you might just need a catch can simple fix and inexpensive.

To test, just get a coke bottle or something and see what happens, take the pipe off that goes back into the intake

[R32 TT]

blowby, thats the usual one. if the rear seal is gone then it wont have oil in the intake side

sounds like you might just need a catch can simple fix and inexpensive.

To test, just get a coke bottle or something and see what happens, take the pipe off that goes back into the intake

<{POST_SNAPBACK}>

Yup. Well. Now she's had a compression test and it looks like I've all but lost number 2.

The question on my mind now is if I had have had a catch can, might this have been avoided?

[R31Nismoid]

no

[R32 TT]

no

<{POST_SNAPBACK}>

Well - actually that's kind of good to hear. At least it wasn't something I could have "easily" prevented.

Cheers,

guess its reuild time.