How does a BB turbo work?

[Frankenstien]

Frankly I feel this is a gimmick. A tripple or even quadruple ball bearing is simply sharing the axial load through a set or two sets of duplex pair bearings.

Instead of one bearing controlling inboard thrust and the other controlling outboard thrust you now have two controlling one way, and one controlling the other or vise versa.

Make sense?

So wouldn't a QBB be the way to go? 2 bearings for inboard and 2 bearings for outboard? I wouldn't think there'd be much sacrifice in spool time, but there would be an increase in longevity due to the equally divided strain on four bearings rather than two?

I also have another thought on this: Would it not be possible to get more longevity out of a turbo by making one with both journal bearings and ball bearings? Or is that not feasable?

 

[Frankenstien]

^ Just curious if it's possible.

 

[Doward]

What would the journal do, that the ball bearings were not already doing?

 

[Frankenstien]

I don't know, maybe having a journal in there would keep the turbo from failing as fast as an ordinary BB turbo? Just an idea I've had floating in my head for a few months.

So having said that, would a BB turbo with 4 bearings rather than 2 (DBB vs QBB) be better longevity wise, comparable to a journal bearing perhaps, or even longer maybe? I think it's a good idea.

 

[gaboonviper85]

I'm no expert let me just make that clear..

I don't think it matters how many bearings you have....the fact is that ball bearings have moveing parts....yes ball bearings have less resistance but let's say that your turbo is spinning at 100,000 rpm those bearings are produceing massive ammounts of heat and need to be cooled (aka oil flow)... A little hickup in the flow could be enough for the bearings to cook themselves......not only that but you get the slightiest ammount of dirt in the oil and it makes it to the super high precision bearings they are toast...

A standard bearing has no parts...shaft just rides on a pocket of oil...nothing to wear out....nothing to break....nothing to generate heat....although this setup sucks for boosting it's a superior design with our oiling systems....

Now if we could have some auxillery turbo oiling system that had it's own pump and it's own oil then bb turbos are risky.

Again it doesn't matter how many ball bearings you have as they don't see much load anyway...the only load is in the compressor and turbine...

This is my "guess".....I make parts that spin well over 100,000 rpm...spin so fast the bearing races need to be bolted to the parts themselves and the bearings are custom made,,,$6000 a bearing....

 

[bmoss85]

Now if we could have some auxillery turbo oiling system that had it's own pump and it's own oil then bb turbos are risky.

not a bad idea, probably wouldnt be hard to do. electric pump and an external reservoir. iirc sts turbo kits use an electric pump to get the oil back to car from the turbos. but if that pump were to fail well, it would be time for a new pump and turbo.

 

[Adjuster]

I thought about hooking up my oil feed line from the bypass filter.. The oil would be as clean as possible, and it would restrict flow somewhat, to keep oil smoke down on the turbo.

In the end, I just used a restrictor oil fitting, and it seems to be working fine.

I'd need some idea of how much oil is being filtered through the bypass filter before I committed a turbo's life to that flow. (Right now, I'm just dumping the bypass filter oil back into the pan, via the stock oil cooler location fitting.)

The rest of the oil goes through a Canton full flow filter that's rated to 8 microns. (The bypass is rated to 1 micron or better.)

Oil Guard, the bypass filter guys, say about every 45 min of use, on most vehicles, the oil is all filtered through the bypass filter. However, the amount of oil pumped through the engine in that time is actually quite a bit, as flow rates in your engine oil are very high.