Announcement

Collapse
No announcement yet.

Turbocharger Machining...

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Turbocharger Machining...

    Hey guys, I wanted to pick your brains a bit on how exactly you would perform this task. I have a good idea of my own, and I think it would be effective, but I wanted to see how you would approach it. I have a small diesel performance business, and we have pushed the stock type turbos beyond what we have the fuel for now. I and a few other guys have built custom setups to run bigger turbos with great success, but the biggest complaint from the crowd is that they dont want to spend the money/modify to accommodate a custom setup... My solution to this is to use the stock "hot" side setup, and graft a more modern series of turbos (Already have them picked out) into the stock turbine housing (Which is sized just about perfect for the new turbo). I have already done most of the dirty work in figuring out how to go about it, the issue I am at all apprehensive about, is machining the Radius in the bore of the housing like below:



    It is about 45* of a 1/4" (or so) radius, and I am worried that just grinding a radius tool, and boring with it on my 10x22 lathe, or with my boring head on the Round column mill is going to result in a lot of chatter... In fact I know it will, so I am not even going to entertain that idea.

    Being that the turbine wheel is going to be the same wheel for both turbos I plan on upgrading to, I am thinking about making a cutter with the radiused profile that will ride on a pilot, very simlilar to a valve seat cutting setup, and have a base that the housing will clamp to, and index off of the exducer bore....

    My question is, how would you do it?

    Thanks,
    Justin
    Justin Anderson
    Fortynine Industries

  • #2
    I would mill it on a rotary table using a 1/2" shank carbide wood router bit spinning as fast as the mill spindle will go.

    Comment


    • #3
      I do turbo work. I use a radius tool (wood router bits) and go at it. You can't go at the radius right on, you first plunge into it from the side and then bore bigger so you are really only cutting half the radius at a time.






      Now if you plan to do this job ALLOT and pump out 20+ turbos a month for years I would maybe look into building a specifically designed for that op tool, something similar to a ball turner.


      Lots of turbo companies just find housings from other turbos (stock auto manufactured) and slap them together. I thought it was hilarious when a buddy said he finally got in his $1500 super special turbo for his car. After seeing it all it was is the cold garrett housing from a ford 7.3 mated to the cars original hot side and wheel. I said, "yup, looks like a nice turbo".
      Andy

      Comment


      • #4
        This is the hot side, ie cast iron. How do you guys get the whole exhaust casting fixtured in the lathe? Tolerances on that surface are very tight, a score can ruin efficiency, and if the exducer ever touches the housing its junk.
        I know someone who had his intake housings reprofiled to put a hybrid impeller (a garret super60 I think it was) in the intake side of a mitsubishi ht10b (kawasaki 750 turbo bike turbo), and he said the only way to get the accuracy needed for the turbo clearances at various points of the profile for it to actually work properly was in a special cnc lathe programmed especially for the job.

        Comment


        • #5
          Turbos actually have huge clearances around the wheels as far as machining goes. I would say a "tight" turbo has a good .020" or more gap all the way around the wheel, even more clearance on the hot sides. That is like the grand canyon.
          Andy

          Comment


          • #6
            My 7.3 turbo, notice the huge gap all around the wheel, that gap stays the same from top to bottom. This is normal for pretty much all turbos.

            Andy

            Comment


            • #7
              Swung this housing on my lathe after cutting and welding.





              Andy

              Comment


              • #8
                Interesting video
                http://www.youtube.com/watch?v=A5abkwIhTz0

                How would I do it? I'd make a fixture to hold it in the lathe as I don't have a cnc machine, and cut a profile tool to exactly match the shape of the original housing (its not a straight bore, its a profile, if you listen to the video you can hear the stepper going on the lathe generating it) then I'd cut it to the profile with the profile tool. Material is spherical graphite iron. That way they've done the research into profile for you already. I'd copy their tip->housing clearances too from a new unit.
                If you change the profile you cut at any point along the impeller, it alters the flow of the turbo through the map. Reprofiling is a bit of a black art and a closely guarded secret.

                I talked to my friend about the profiling tool option when he was having the housings reprofiled as I always have a eye on how I might diy something myself to get out of a hole in future, and he said he thought it was possible but neither of us have done it. I would make the tool the biggest section I could get in there with sufficient clearance and still bolt in my tool holder. Rigidity is going to be the key to sucess. Another option we tossed around was putting it in the mill on a rotary and rouging it in, then finishing it in a dedicated fixture on the lathe.He only had about 4 units to do so just stumped up for a dedicated shop with a cnc lathe with a profiler to do it first go.

                Comment


                • #9
                  So you want to take a new upgraded cartrige with compressor and fit it to the oem turbine housing?

                  If you modify the turbine housing to accomidate a larger wheel you risk making the turbo very inefficient
                  Generally speaking an exhaust wheel is suited to a few diff. a/r sizes of housings, which maps are always available.

                  Have you talked to ATP about this mod? They might offer some insight to what your end result might look like.


                  If it were me doing these mods i would be looking into an adapter plate to mount a new turbo on the existing manifold.
                  Something with a small profile to minimize moving components much.

                  This way you can choose a proper turbo to get you to your goal with no variables.

                  I know what you mean about people not wanting to spend the money to do things right. This is the exact reason I stopped building custom turbo setups.



                  regarding peoples comments about axial play and clearance. this will vary depending on if the turbo is bb or oil bearing. service limits are available from oe manufacturers
                  https://www.flickr.com/photos/csprecision

                  Comment


                  • #10
                    Sorry for the late reply...

                    The turbine wheel is a P-trim wheel, which actually works well in a .82 T3 WG'd housing, so its no issue...

                    The idea is to have a bolt on modification for the factory turbo setup, so adapters and whatnot are just not an option, the fatory DP has to bolt up, and it has to maintain the factory WG (which I plan to produce and upgrade for)....
                    Justin Anderson
                    Fortynine Industries

                    Comment


                    • #11
                      the oem turbine housing is T3?

                      What vehicles are we talking about here?
                      https://www.flickr.com/photos/csprecision

                      Comment


                      • #12
                        Factory Turbo 7.3 IDI 93-94...

                        Factory Turbo is a T04B-H3/T3 stg 3/.82 Hybrid....
                        Justin Anderson
                        Fortynine Industries

                        Comment

                        Working...
                        X