For a lot of basic information about the Mazda 13B engine CLICK

Until we have time to properly write this chapter, here are some pictures of our engine, first with the 1.3 A/R center feed turbine housing, second with the 1.15 A/R divided tangental feed housing to pull the turbo closer into the engine for a cleaner cowl line. 
...and yes, it's in our living room.

With Turbonetics TO4E-50, 1.3 A/R, P trim ceramic ball bearing water cooled center section:

And same turbo but with a 1.15 A/R divided tangental turbine housing: