oil through the blow off valve and sometimes smoke at cold start
 

...any chance its not a blown bearing?

I just put a .060 restricter on there when I shoud have put it on from the start.

could it be your restricter? most run them in a .035 diameter

I have no real axial play, no radial play, so I suppose that's an option. I should note that I have a funkily shaped oil return...maybe I should convert to hardlines. Right now the return does not "point down", its more flat from the turbo to the drop.

If its blowing oil into the compressor is it already too late?

Do some hard lines on your return. I get a little smoke from the exhaust if I'm at a weird angle or sometimes at start up. Wouldn't worry too much about it. Usually clears itself up. It's on the list of things for me to do as well.

Michael

um...
https://www.miataturbo.net/forum/t40085/#post466476