Important tip when installing BB turbo's

[Russco]

Guys, when upgrading from plain bearing turbos to ball bearing ones make sure either yourself/mechanic installs oil restrictors in the oil supply lines, you can get these from GCG - HKS kits will inculde these but most ones purchased second hand will not.

[czy18e]

Why is this?

[Russco]

Why is this?

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.

[R31Nismoid]

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]

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.

[Russco]

Sorry - maybe this only applies to older HKS units like mine (2530s), not the newer GT series.

[R31 POWER]

I also had to add a restrictor to my HKS GT2535.Looking down into the oil cartridge feed it had a small hole but meh it has a restrictor now

[Amaru]

Possibly a stupid question, but I thought the 2530 was a GT series turbo (ala HKS GT2530).

[GTR-Ben]

He said it has a small hole, but added another restrictor.

The small hole in the feed is the restrictor

[R31 POWER]

So is this bad that mine has a restrictor in the oil line and in the core?

[GTR-Ben]

Well if the extra restrictor is the same size or bigger then it shouldn't matter. If it was smaller than the restrictor in the core.. it could be not getting enough oil.

[R31Nismoid]

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]

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]

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.

[Russco]

George, this isn't it - they are only about 0.036" in diameter.

[DAN00H]

anyone with 2530's (or the like) that is experiencing oil issues??? I imagine the replacement turbos would have the restrictor inbuilt?

[Amaru]

Have had 2530's in mine and done 15000km on them without a problem. Hi boost setting is 1.5 bar, low boost is 1 bar.

[yogi000]

i havent put mine on yet, but i'll take it to gcg and see what they say before i put it on.

[DAN00H]

seems odd that the GT series turbos would have such a design 'flaw'

[R31Nismoid]

yogi000

That isnt the restrictor. As i said, its internal.

you cant see it unless you pull the cartridge apart and look at the bearing casing (or something like that)

Mine is .7mm