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Old 12-19-2012, 06:35 PM   #1
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Unhappy ITT: how much abuse can a compressor wheel take before BOOM?

Pretty much what the title says.

Take a look at this compressor wheel, and tell me what you think:


Spins freely. No excessive shaft play. Edges (where it gets close to comp housing) are fine. Just the tips of the "face" are chipped up as you can see.

So I want as much feedback about this as possible from those that know or have experience, or have heard about this type of stuff. What do you think or know?

Thanks
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Old 12-19-2012, 09:50 PM   #2
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1 day.
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Old 12-19-2012, 09:56 PM   #3
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What causes that? Sand?
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Old 12-19-2012, 10:51 PM   #4
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Id run it.
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Old 12-19-2012, 10:58 PM   #5
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I've run worse for a long time lol. No housing contact on it, and it had a couple corners missing from blades...like 4-5mm cut off diagonally.
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Old 12-19-2012, 11:47 PM   #6
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As long as it runs smooth . . . .

But your compressor efficiency is going to suffer.

What did it eat?
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Old 12-20-2012, 12:59 AM   #7
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I thought that's how they came.

Run it till it wobbles.
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Old 12-20-2012, 02:22 AM   #8
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I'd say, as long as it's balanced properly it should last a longgggg time.
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Old 12-20-2012, 05:37 AM   #9
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tis nothing but a scratch, whelp.
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Old 12-20-2012, 10:17 AM   #10
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While it does a helluva job at it, you really need to stop using the turbo to turn wheat into flour.
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Old 12-20-2012, 10:21 AM   #11
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LOL Interesting replies. That's not my turbo. My theory is that a tiny rock or metal particle went in there when that sucker was at 80+k rpm and bounced around a bit before getting stuffed into the engine
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Old 12-20-2012, 10:32 AM   #12
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My honest answer is, if the shaft play is minimal, use a dremel to take off the rough edges and run it. Also, I would also recommend buying dye penetrant and test for additional cracks in the veins beyond the obvious. It's typically not the obvious flaws that cause the catastrophic failure; it's the tiny hairline fracture that propogates and explodes into the engine.
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Old 12-20-2012, 10:35 AM   #13
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I considered "deburring" it or sanding it or whatever
the thing that makes me a bit nervous about that is throwing off the balance of the assembly by perhaps removing a little more from 1 fin than the other. is that just my OCD kicking in?
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Old 12-20-2012, 10:47 AM   #14
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balance. funny.

my last T3 had 3 different compressor wheels on it at one point and had been pulled apart and rebuld once.

Went I ate a screw, I replaced the turbine wheel/shaft.

did I balance it? no.
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Old 12-20-2012, 10:47 AM   #15
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A discontinuity in the metal creates a stress concentration. I personally would prefer to debur and potentially save he wheel from failing. Consider that the balance may already be out of tolerance. If the owner does not want to replace the compressor wheel, it would be safer to burn the bearings out through an imbalance than destroy the compressor (and possibly the engine?) by leaving it rough.
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Old 12-20-2012, 11:13 AM   #16
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Quote:
Originally Posted by Braineack View Post
balance. funny.

my last T3 had 3 different compressor wheels on it at one point and had been pulled apart and rebuld once.

Went I ate a screw, I replaced the turbine wheel/shaft.

did I balance it? no.
If this was a $150 turbo I wouldn't care either lol.

Quote:
Originally Posted by cymx5 View Post
A discontinuity in the metal creates a stress concentration. I personally would prefer to debur and potentially save he wheel from failing. Consider that the balance may already be out of tolerance. If the owner does not want to replace the compressor wheel, it would be safer to burn the bearings out through an imbalance than destroy the compressor (and possibly the engine?) by leaving it rough.
I was thinking fine grit sandpaper or a small file, and just go over each blade lightly taking off the same amount as consistently as possible.
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Old 12-20-2012, 11:28 AM   #17
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it was a real garrett.
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Old 12-20-2012, 11:29 AM   #18
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Quote:
Originally Posted by Braineack View Post
balance. funny.

my last T3 had 3 different compressor wheels on it at one point and had been pulled apart and rebuld once.

Went I ate a screw, I replaced the turbine wheel/shaft.

did I balance it? no.
When I rebuilt the sr20 that's currently on my car like 4 years ago...I did not balance it either. It's still running flawlessly to this day. Do I still believe balance affects radial motion? Of course I do.
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Old 12-20-2012, 11:42 AM   #19
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But if I was buying a used BB garrett from someone, id be a little hesistent to buy it...
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Old 12-31-2012, 05:13 PM   #20
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exactly 22.3psi...

doesn't look great, but I'd rock it
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