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Important tip when installing BB turbo's

Russco

By Russco,
in Engines & Forced Induction

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

did you know... that a Garrett BB has an internal restrictor on the turbo cartidge itself :)

There is no need to fit to a GT series one thats for sure. Id be farily confindent a lot of others would be the same too

My GT30 has an internal .7mm one from the factory :(

BBQ Community Regular

BBQ

Posted
Posted
Without a restrictor the turbo gets too much oil, which at high revs/boost forces oil down past the seals which gives you a smokey exhaust. This happened to mine at over 5000rpm using only 0.6 bar boost.

I'm pretty sure you don't have to have a restrictor for it, as its all ready built in. (as r31nismoid said)

The only way yours could have done that is if, the oil seal was too old and on its way out, or you have lots of blow by happeing causing it to break the oil seal.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

the one that you can see is only the half of it.

there is a smaller one inside the actual cartridge.

I've seen mine as my turbo was ripped apart, and being garrett make HKS turbos i cant see it being any different

yogi000 Mentor

yogi000

Posted
Posted
the one that you can see is only the half of it.

there is a smaller one inside the actual cartridge.

I've seen mine as my turbo was ripped apart, and being garrett make HKS turbos i cant see it being any different

Hey guys,

look at the pic, its a old style hks gt2530. Is that the restrictor in the picture??

I'm under the impression that it is.

Thanks

George

Warpspeed Experienced

Warpspeed

Posted
Posted

There probably is a specification around somewhere for minimum oil flow, but I have no idea what it is for ball bearing turbos, probably not very much.

The old sleeve bearing turbos that are oil cooled need half a gallon of oil per minute at fast idle (full oil pressure). But these sleeve bearing turbos use oil for cooling as well as lubrication. They usually have two 1.0mm restrictor holes in the front thrust bearing.

It is quite easy to disconnect the oil return to the sump and measure the actual flow into a container. Too much flow is not a good thing for two reasons. It steals oil from the rest of the engine, and lowers idle oil pressure, and all that oil has to get back out again. If it cannot escape easily, it is going to find its way out past the seals as has already been mentioned.

Ball races only need to be wet with a thin oil film, they don't need to be drowned in oil. The water in the bearing housing will carry away all the heat. I doubt if oil starvation is ever going to be a problem, unless there is a total blockage. But too much oil is probably a worse enemy.

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