Turbo Stockers

[Rob Lloyd]

Originally Posted by Jimi B

I wouldnt be real concerned with it. You know you have a stock turbo. Just get the correct rebuild parts. As far as that dia of the inlet.. It says Turbocharger size will be verified by measuring the housing bore at the leading edge of the impeller wheel. So basically measuring the dia. of the inlet right at the front of the compressor wheel. If you are not aloud to change the wheel I dont see much need play with the inlest size.. Not 2mm anyway. Every little bit helps I suppose. But I would think that you would want the tolerance to be tight right at the wheel...

I'm not to worried about the compressor side. It's the turbine I'm worried about. I have a good turbine housing, but all of my turbines measure at least 0.04 smaller than the housing at the exducer. I think maybe my turbines are worn down pretty far. My guess is it should only have 0.01" clearance, but I don't know for sure what the turbine is supposed to be. I found some specs that say it should be 1.88" - mine measure more like 1.84". Ouch! But, again, the housing bore measures close to 1.88" So, I don't know if that spec is for the housing or the turbine.

You definitely do NOT want 2mm clearance around the compressor. It will cause a very slow boost rise. You want as small a clearance as you can run on the compressor side.

Related question - Art, did you have trouble seizing the wastegate arms? I seem to seize one up every single season. The 'good' turbine housing I mentioned above I shelved because it seized the WG arm. I took it apart and reamed it out, but I'm concerned it will just seize up again. I reamed it with a 5/16" drill (the arm measured 8mm, so there's alot of clearance now). Just gotta get the arm welded back up and put my 'good' turbine in there for Indy...