GT30 oil feed

[loner]

Who is using a restrictor and who is not and why for each case?

[boon]

I had one for a little while, the answer is no, if it's a GT30R (R denoting a ball-bearing core) then the core has a restrictor orifice in it, just use a -3AN or larger.

EDIT: Caveat, unless you have ridiculously high oil pressure for some reason, or a terrible oil return that can't be remedied, or high crankcase pressure making the oil not drain well. Long story short if it DOES leak you can always just add a restrictor somewhere like the banjo, or weld up the AN fitting adaptor on the turbo and drill it out again with a small hole.

Edited February 3, 2016 by boon

[loner]

I have oil consumption problems and high oil pressure (80 - 90 psi). I have a Garrett BB turbo install guide (below) that states if the

oil pressure is higher than 60 psi a restrictor is recommended, so don't want to even try running without a restrictor.

I have no idea how to calculate the restrictor size.

https://www.scribd.com/doc/297699139/BB-Turbo-Installation

[boon]

Do you have the turbo off the car? One look in the oil feed hole will tell you if it has a built-in restrictor or not.

And one look in the turbine housing will tell you if it's pushing oil through the seals, it will be black as on the bottom half because it will ooze oil after shutdown and the turbine housing material is slightly porous (or at least it is to something as thin as hot oil)

But yeah, BB turbos require bugger all oiling so you're unlikely to hurt it by running a restrictor... I'd run a 1mm.

[loner]

I haven't fitted the Garrett yet... it does look like there is a restrictor in it, but it's just confusing when the instructions say to put a restrictor

in there and makes me think an additional restrictor might be required.

The current turbo has no obvious signs of oil escaping on the exhaust side, but there is oil coming through on the compressor side... along with small bits of metal.

[boon]

 loner said:

I haven't fitted the Garrett yet... it does look like there is a restrictor in it, but it's just confusing when the instructions say to put a restrictor

in there and makes me think an additional restrictor might be required.

The current turbo has no obvious signs of oil escaping on the exhaust side, but there is oil coming through on the compressor side... along with small bits of metal.

One way to look at it is you're not going to hurt it by adding a restrictor, so just weld up the AN adaptor for the oil feed then run a 1mm or 1.5mm bit through it.

But it also might be completely superfluous - up to you

[Tony]

Speedflow make restrictors which fit into the top of -3 and -4 flare fittings. They are a small alloy piece which sits down inside the fitting. It's an easy way to add a restrictor without welding and drilling the fitting. I have a -4 line to my turbo and use one of these restrictors in my set-up with no issues.

I will try and find the part number if you are keen on going that way?

[loner]

Thanks. These? http://www.speedflow.com.au/restrictors.html

[Tony]

Yep, that's the ones

[Optical]

I flooded my old gt28 with no restrictor and fed with a -4AN line. A 1mm restrictor sorted it.

Edit - that exact aluminium plug in thingy in the Speedflow link

[Ninja8)]

I run a 1mm restrictor in my 3076r...it states in the garrett website to use one for BB turbos. I was stumped too whether to use one or not. Did check with engine builder too just for clarification

[loner]

The Garrett docs are pretty vague at best... anyway Road & Track are putting a line together for me and are using one of those speedflow restrictors.

I'm also having a port for a pressure sensor put in the line after the restrictor so I can be sure the pressure is correct.

Thanks for the advice.

[Guest]

Bbbbbut garrett are market leaders...derp. Remove adaptor port thing after youre done?

[loner]

maybe, or just block it off.