Chipped compressor wheel, rebalance?
 

O'k, the never ending turbo saga continues... Despite my coffee can sized K&N filter I somehow managed to damage my compressor wheel. One blade has a ~1/32nd" vee shaped chip out of it, and some tiny nicks on some of the other blades, less than a 64th" in dimension. The compressor housing has some tiny nicks as well from whatever it was bouncing around in there. There is the usual amount of shaft play, and I cannot make the blades touch the housing. That said, at WOT the turbo starts to scream as the blades touch the housing.
I am assuming that when spinning at ~75,000rpm the compressor is wobbling, allowing the blades to just barely touch. It happens on the track after long sweepers, followed by WOT, but not on the straights, WTF... anyway, I am wondering if I should just clean up the nicks in the housing, and have the compressor re-balanced? Thoughts????
I would like to spend as little as possible to get my broken turbo to last as long as possible. Alternately, is it possible to just replace the compressor assuming there is no other damage, or does the fact that the blade can touch under WOT mean the bearing is toast? I ran the turbo three 20 minute sessions after the noise began, with ~5 seconds/lap of interference I could hear.

Thanks, Carl

When I ingested a FOD and chipped/clipped my compressor wheel the local master Garrett distributor was able to check the turbo and bearings out and answer my versions of your questions. They could have soaked me for a rebuild. They just replaced the compressor wheel (with the one that was SUPPOSED to come with the GT40r, the 54 trim rather than the 56 trim) and sent me on my way.

Moral: a good dealer with a service center will hold your answers.

Mine was Columbus Diesel Supply.

Thanks, That's the direction I'm heading, I just want a little insight, so I don't get hosed. How much was the compressor? Carl

carl,

i suggest you call kevin draper at majestic waco tx. i have dealt w kevin for 3 years on numerous matters and he has always been straight w me and is a racer. he built, among other things, the turbos for racing beat's bonneville car that tried to leave the planet.

he knows rotaries. he knows turbos. make sure to mention my name 800 231 5566.
btw, kevin will be happy to advise you at length re your turbo.

good luck,

howard

Compressor wheel was free since Garrett took so long on even finding the part...plus it seems my turbo had an interesting history and should have never been released with the compressor wheel I had on it.

Labor was right around a c-note including the inspection and checking. I thought I would have to pay for a new balance. Nope.

Tony

I didn't think you could reliably replace the comp wheel without rebalancing the assembly.

I had a similiar problem on my first turbo (TD07-25g). I'm sure the problem ended up being with the K&N filter itself. I ran it directly off the comp housing and the filters mounting flange cracked and some very small pieces were missing that were safe to assume had broken off and been eaten by the turbo. This was caused from the heat/vibration of the turbo itself and the shitty flange on the K&N. I now have a 90' 4" silicone hose mounted between the filter and comp housing. It absorbs the heat/vibration and as a bonus, relocates the filters position so I am no longer sucking in air after it has passed through the radiator.

I ended up saying fuck it and ran the turbo in that condition for about a month longer and ended up killing the chra bearings. Also, there was noticable wear between the comp blades and comp housing. I don't think finely ground aluminum shavings are the best things for the motor to ingest.

That was three turbos and four engine builds ago....

...and that's why I had the experts check it. Guess what? Been on there for 7 thousand miles spooling up to 22psi and 8600rpm.

"Hard to believe" versus fact. Turbos and manufacturers are different. And so would be the FOD and what you did after the damage.

The FOD was from my cheapie Greddy'esque air filter at the time. A small plastic tab broke loose. Now I have a truck K&N mounted under the right headlight with 4" industrial heat-proof-no-kink tubing to the compressor.

depends... the bigger they are and the faster they spin, the more important balancing becomes.

Unfortunately Kevin "is not around for awhile" according to Majestic, they suugested I take it to "someone local" LOL.

http://www.forcedperformance.net/

Talk to Robert Young (the owner)

(972) 984-1800

EXCELLENT turbo facility to do business with. HIGHLY recommended.

I would stay so far away from Majestic, et al it is not even funny.

Tell him MikeG from TeamNABR sent you!

Mike

Well, after a bit of research, the best option, and the simple fix is to simply order a new compressor wheel. They come balanced from Precision, so 132.00 + shipping, and I am done. I for one did not realise you could simply bolt up a new wheel. this is like the deal with smoking turbo, that has been run at too high an oil pressure. It is not "blown", just filled with oil. Clean it up, fix the oilling issue, and you are good to go. Later, Carl

As a side note, that wheel is supposedly made for Precision. I talked to the local shop, and they stated their cost on it was 123.00, and wholsale was like 160.00+. So it pays to shop around for various wheels depending on their origin. Carl

Master Power T70


-Ted