I bought the Stage III kit from htturbo.com. It came with the compressor wheel and the housing. Today, I went to do the install and found out that the bearing section, the center housing section, has to be machined to accept the larger compressor wheel. I was not aware of this at all.

The old wheel size was 78.00mm and the bore size on the center section is 79.50mm.

The new wheel size is 85.90mm. Should I have the machine shop machine the bore size 1.5mm to 87.40mm or what did you guys do?

Help.

 

I had mine machined by a machine shop, but cannot remember how much. And I can't find the spec sheet that came with mine.(bought from a different company than you) You could call HTT and I'm sure they would tell the amount. It seems like mine had an in between number (ex. no more than a number and no less than another) Sorry I wasn't more help.
Good Luck
Cory