Hi guys,

I was taking my stock twins apart with the intent of porting my wastegate and ran into a few issues. I separated the turbos and found these cracks :

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There's also a crack on the lower wall inside of the wastegate port.

One of the bolts holding the housing together snapped (top of first pic), and I also noticed some shaft play with the front compressor wheel. Should I consider these toast and not waste my time trying to extract the stud and putting them back together?

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Pretty common for well used s6 turbos. I believe they changed the metallurgy in later iterations to mitigate similar issues. It's not optimal, but the turbos won't really be affected if you want to run them like that. I'd be more worried about shaft play; how much is there?

Better sets should be available relatively cheap, if you have a little time on your side.

 

If your in a pinch you can use them until the cracks get past the gaskets, thus causing an exhaust leak. All N3A1, 93-95, turbos crack like this. Did they hold boost ok? Did they smoke? How many miles on the turbos?

 

My secondary transition and boost seemed weak. Running a Pettit ecu, I went from a consistent 12-10-12 pattern to 12-7-9. I'm not sure what the mileage is on these, but the chassis has 92k and 25k on its rebuild.

 

Based on the cracks they are probably the original 92k mile turbos. Boost pattern could be many things, might not even be related to the cracks at the waste gate.

Situation depends on if you want the car running asap, you will be fine with those for awhile. If you want a winter project locate a low mile set, port the waste gate, and go over all the sequential controls.

 

Pretty common and those cracks aren't that bad. If you are on a budget and they boosted ok I'd run them. Boost pattern issues are usually control issues related to the solenoids or vacuum hoses, not the actual turbos. Otherwise I would look into a set of BNRs with new housings.