not all that interesting an article after all, as all they did was talk to owen developments about what they do, and they are not the be all and end all in the world of turbocharging

what was interesting was that the WRC turbos use roller bearing cores

and that due to the restrictor, the compressor wheel tends to be built especially deep rather than large diameter. so what looks like a small compressor wheel in terms of diameter will still have a high volume flow rate due to it's overall volume pushing ability from it's greater depth