Smoked a new GT3071r after 800 miles

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  • 90/90qs
    S2Forum Addict
    • Jun 2006
    • 244
    • Country: United States

    #1

    Smoked a new GT3071r after 800 miles

    Well, I had a good run at it... After 4 years of effort I finally got my project 90 on the road this last summer, and proceeded to get into tuning (034 IIc). I spent a few weeks fixing up the clunks and bumps and did tuning on and off in the meantime; 2 weeks ago I went with a friend to do final tuning before spending money on a dyno sesssion and we spent about an hour driving the freeways. Finally the fuel map started to develop some trends as hoped, and we finished with a few pulls just shy of 200kmh. Happy with the results, I pulled off the freeway and started hearing some noise which I thought was wheel rub. I'm running coilovers so I was not immediately worried, but as the sound continued to appear at odd times such as straight line driving, I payed a little closer attention. The gas station was not far off the freewway exit and I pulled in to fill up and have a look, but when I sht the engine off it was all too clear where the noise was coming from ...
    I have no idea what happened upon disassembly there was residual oil in the lines, and coolant in the coolant lines. I blew through the oil feed line to make sure there was no debris in the oil restrictor, and there was not. I was only running 20lb boost, regulated by an N-75 H, so I don't think I over spun it.
    One think that may have contributed was that I dinged the compressor exducer wheel one day while working on the turbo. (Bad idea to have the housing off while servicing...). The damage was not incredibly severe, and I did my best to gently straighten it out with pliers wrapped in duct tape.

    Anyway, after crushing my hopes and dreams it is now time to regroup and decide on a course of action, so I'm considering turbo options.
    I've found a superceeded GT3071r CHRA for half the price of the 'new' model: part number 700177-5022 (superceeded by 700177-5023) and I have read that these are interchangable. Price: $450 (amazing price, or so it seems)
    I could also buy a new (700177-5023) CHRA for $900+ from numerous retailers

    or alternatively I could go a different route all together. I like Bram's comments on the CT355, but I can't find reference to that turbo except here. I did find a few that seemed to fit the description:
    CT3-5152
    CT4-5862

    both of these look nice, but no reference to the price with available bearing upgrades and such, so I was wondering what models people have tried (and if one of the above is the CT355) and what one could expect to pay for such a turbo.

    Last piece of logistical data, I have the Wagner EM with Garrett flange and a custom v-band exhaust. My old turbo is a garrett 4 bolt outlet with a 3" v-band adapter. I would like to Not have to rework my exhaust to make it fit...

    Any Suggestions?
    -Happy Holidays folks!
    http://s260.photobucket.com/albums/ii11/minipitt1/
  • Bram
    S2Forum Fiend
    • Aug 2006
    • 2582
    • Country: Netherlands

    #2
    CT5662 is the same as CT355. At CompTurbo they still have sales with reduced prices and a free Billet wheel upgrade. Go for it now you can.

    Comment

    • Billman
      S2Forum Freak
      • Nov 2004
      • 4129

      #3
      go for a CT.

      The damage came from the dented impeller. Most probably it came out of balance or the drop and hit damaged the bearing(s).
      Go Holset or Go RS4

      Comment

      • 90/90qs
        S2Forum Addict
        • Jun 2006
        • 244
        • Country: United States

        #4
        That is my guess as well, but it was a very minor bend on one or 2 of the fins. -I didn't drop it, I was pulling the comp housing off and wedged it against the wheel. I know a small variance can make a huge difference at that rotational speed... But what is one to do? Seems if you sneeze on the wheel, you may ruin it!
        Another lesson learned the hard way.
        http://s260.photobucket.com/albums/ii11/minipitt1/

        Comment

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