Turbo: If the Precision turbo you’re talking about uses a Garrett cartridge from one of the turbos I listed, then yes. That’s all they have so far, but they plan on expanding this line in the future.
I’m not sure what you mean by converting the a/r since that ratio is measured the same way as usual. I’m guessing you’re asking how a .82 a/r Garrett exhaust housing flows compared to a Tial .82 a/r exhaust housing. Since they don’t post that data your guess is as good as mine. The inlet size on a GT35R turbine housing, for instance is 2.5" (pipe size not vband flange size) and 3" outlet (again pipe size), so that’s pretty comparable.
-Mike