ZX-Tex

iTrader: (15)

So I called Corky at BEGI today to discuss what observations he had of the destroyed GT2871 turbo I sent back to them. We talked about this and that, what might have caused it, and so on, then he stops in mid-sentence and says something like "Wait a minute... there is no nut on the end of the shaft at the compressor..."

Huh? Seriously?

So just to be sure that one is supposed to be there, he grabbed a GT2860 they had on hand and verified what he already knew, that there should indeed be a nut there. Mine is gone. That would explain what trashed the impeller. Long story short, I checked a picture I took of the turbo before I installed it and sure enough there is a nut on it. I also checked a picture I took right before I removed it from the car. Sure enough, no nut.

Before:


After:


I did not notice that it was missing before I sent it to BEGI
I removed the pre-and post turbo ducting and intercooler today and did not find the nut. So either it fell out before unnoticed when I had the ducting apart, or it was completely destroyed, or it is stuck in the turbo (impeller blades or compressor housing). So the leading theory of the cause of death is that the nut came loose, hit the compressor impeller, knocked chunks off of the blades, caused a severe imbalance, which then overloaded and destroyed the bearings. This is no fault of BEGI of course, since they just buy the turbo from a supplier; they do not build them.

Now before you ask, no I did not loosen or otherwise mess with this nut in any way. No reason to. My question is, has anyone ever seen a nut come off spontaneously like this before?

Cspence

iTrader: (11)

tyson87

iTrader: (6)

i get my nuts off every once in a while......

sixshooter

iTrader: (12)

+1

Braineack

iTrader: (62)

Inspector 53 should be fired.


Hell I've run a regular pitched threaded turbine for years and it's never come loose.

Hi Im Simon

iTrader: (18)

holy crap, that sucks.

may i ask why you selected the anti surge?

ZX-Tex

iTrader: (15)

I'm all for 'getting my nuts off', but not like this. I hope I am not 'screwed' but it looks like I at least got 'shafted'. Hopefully the supplier does not try to 'spin' this in their favor and leave me 'hanging' after 'blowing a lot of hot air'.

Perhaps I should 'compress' my response.

ZX-Tex

iTrader: (15)

Cuz its hella kewl, all da playaz has wun, and maKes a DopE noiZe dAt dA biTcHes luv.

But seriously, for a couple of reasons. It broadens the range of the turbo slightly, and also helps prevent surging, both good ideas for when a turbo is operating at the left side of the map when building boost. I talked it over with ATP tech support, and a former Garrett Design Engineer, before making the final decision and they thought it was a good idea.

Hi Im Simon

iTrader: (18)

i was reading up about the miata and using antisurge 2871 turbo. i was reading up that it wasn't such a good idea or not necessary. i can't remember the facts though.

ZX-Tex

iTrader: (15)

If you can remember what you read and where I would be curious to see it. I read up a lot about it, or as much as I could find, before pulling the trigger. The main two reasons not to do it I found were the additional noise from the compressor (not too bad, and for some that is a 'pro' anyway), and a very slight loss in efficiency, like 1-2% max.

Ported shroud compressors are very common on Diesel turbos because apparently Diesels are able to drive the compressor into surge (upper left part of compressor map) while spooling.

18psi

iTrader: (76)

On a more serious note though: that sucks man. hope you get it all taken care of by the manufacturer

rlogan

iTrader: (21)

Well, at least the problem was an obvious one....hopefully they do the right thing!

kotomile

iTrader: (24)

Wow! That's one trashed wheel!

Of course it's not Begi's fault, but it is their responsibility to work with their supplier to rectify the situation.

Kelly

iTrader: (6)

Had this happen on a 3000 Gt in the shop with freshly built turbos from Alamo Turbo about 5 miles into the first drive with them. They said its wasn't due to an assembly error and made up some long drawn out bullshit about the turbo being stopped and started too quick when the throttle is pushed. Pretty far fetched.

Edit: it was really cool that on this car...the nut went from the front turbo, back through the intake tube and destroyed the rear turbo as well.

Braineack

iTrader: (62)

pdexta

iTrader: (17)

Wow, that had to make some nasty noises. Good luck getting it taken care of.

RotorNutFD3S

iTrader: (33)

Wow man, that's insane. Good luck getting it resolved!

(Hopefully since my car likes to do whatever yours does, my 2871 won't grenade itself like that...)

elesjuan

iTrader: (11)

Uhm??


So should I put some light thread locker on my turbo???? I've been really worried that thing is going to come off, assuming I ever get the turbo installed..

Sucks man! :(

Keith@FM

iTrader: (1)

I've seen that happen on at least one stock Mazdaspeed turbocharger. Never on a Garrett.

chance91

iTrader: (3)

Ahhhh Keith, don't say that! I've run two different stock turbos on my car so far, no problems (fingers crossed!)

As per the guy who mentioned putting thread locker on the nut/shaft, I'd say no for a few reasons.
1) You don't know the torque for the nut, and likely also working on the rotating assembly is very serious work.
2) The nut is part of the balancing process of the center assembly, and they balance it all once both nuts are torqued, so taking it off and putting it back on could cause imbalance, and actually guarantee you have blade failure.
3) Um, I don't know how high the temp threshold of thread locker is, but it may not be as hot as a turbo gets in there on the intake side.


Any resolution from BEGi yet?