Turbo Oil Restrictors

[GTSBoy]

Just wondering under pressure if both examples/ Turbo's would see identical oil flow being dictated by the smaller .8mm oriface @ the block.

For a high volume pump setup

If you are asking, "which will give more even distribution to 2 turbos?" with the options being 1 x restrictor and then splitting the supply, or split the supply and then 2x restrictors, then the obvious answer is 2x restrictors will have to give a better chance of even flow.

[mr skidz]

Uneven distribution of oil happens all through your engine until pressure is up that's normal same as 1 head feed splits off to feed all your cam lobe squiters.

So no not asking about distribution.

Correct outright VOLUME and flow of oil is what I was asking

Edited December 16, 2015 by mr skidz

[GTSBoy]

distribution = outright VOLUME and flow of oil. same same.

I will elaborate on my earlier explanation. You have (pick a number) 4 bar of oil pressure at the block. You put a restrictor there and the flow rate of oil through that restrictor drops the oil pressure to (pick a number) 0.5 bar. That pressure then is directed at 2 turbos. The length of hose, the fittings in those hoses, the details of the inlet angles at the turbos, the details of the outlets on the turbos, the amount of crud that may or may not build up in the oily core of the turbos......all of these things then work as the next restrictions in the 2 flow paths. If one of these is significantly less restriction than the other then it will get more flow. Worse, if one of them changes (ie the amount of crud in one suddenly changes) then the balance of flow will change. In the extreme, if you clog one of the turbos up altogether, then all of the oil will happily flow through the other turbo.

On the other hand, if you have 4 bar at the block, run 1 hose followed by a T followed by 2 lengths of hose all the way up to the turbos, THEN have the restrictors just before the turbos, then your 4 bar is pretty much present all the way up to the turbos themselves. Then the differences in the hoses and fittings all the way up to the turbos comes out of the equation, because the pressure drop across your restrictors is the dominant factor in determining the flow in the 2 branches. Sure, all the stuff in the turbo core and downstream from there is still in play.....but the beauty of it is that you have 4 bar upstream of the restrictors on both legs. If you go close to blocking up the flow path through one of the turbos there is still some good driving force to push oil through that turbo. As flow through that turbo falls, then flow through its restrictor falls and as that happens then the pressure drop across that restrictor also falls and the pressure between the restrictor and the turbo rises - thus increasing the driving force across the core itself and maintaining flow in a situation where the other setup would have stopped flowing.

[mr skidz]

Never mind

Edited December 16, 2015 by mr skidz

[mr skidz]

None of my original question was touched on.

Thanks anyways

[Pezhead]

I tried Banjos from CGC but they weren't the correct size. I took the standard banjo bolts, tapped the holes, loc-tight'd a bolt to the end, cut off and re-drilled to 1mm.

Wasn't a hard job at all.

[scotty nm35]

Loctite doesn't work well with heat, but if you jammed the bolt into the bottom of the tapped thread it should work fine, done it myself on a few desperate occasions.

How did you go with the 1mm drill bit? I have snapped a few off in them too.

[XGTRX]

gcg.com.au

[zebra]

Loctite doesn't work well with heat, but if you jammed the bolt into the bottom of the tapped thread it should work fine, done it myself on a few desperate occasions.

How did you go with the 1mm drill bit? I have snapped a few off in them too.

depends which loctite.

can get thread sealer than needs an oxy acet heat to break it down.

[Pezhead]

Loctite doesn't work well with heat, but if you jammed the bolt into the bottom of the tapped thread it should work fine, done it myself on a few desperate occasions.

How did you go with the 1mm drill bit? I have snapped a few off in them too.

Yup, lock tight and bottomed out into threads before I cut and ground it.

1mm drill is go slow and clear out often and you'll be ok. I used soft bolts to make sure no probs too.

[mr skidz]

What size and thread is it? The M35 Stagea runs 3 x 0.8mm restrictors stock.

question, have you checked yourself to actually confirm the .8mm restrictors size?

And where are they located?

[scotty nm35]

They are actually 1mm restrictor banjo bolts, M12 x 1.25mm.

2 are in the sump, one on the side of the block.

[mr skidz]

They are actually 1mm restrictor banjo bolts, M12 x 1.25mm.

2 are in the sump, one on the side of the block.

so you have 2 on the sump, is that the return oil line from the turbos?

is yours single or twin turbo?

So you have one 1x 1mm banjo bolt feeding the oil is that right?

Edited December 25, 2015 by mr skidz