[Def]

The mixed flow wheel in the 7163 has its efficiency peak at lower Uc/Uo ratios(0.5-0.6). This translates into better shaft torque when the wheel is moving slower relative to the exhaust gas speed than a normal radial flow designed wheel that will typically peak the efficiency in the Uc/Uo range of about 0.7-0.8.

The tradeoff is you'll have a bit more backpressure at high RPM/high boost situations as the wheel falls out of its ideal Uc/Uo range vs. the radial flow wheel that's really in its sweet spot.


That said, at a 500 rwhp turbo on a 2L level, I'm more than willing to throw away a few HP capacity up top for a better mid-range powerband and sooner spool. How often are you in boost in an engine that powerful on our light cars and wishing you had another 10 HP? How often are you out of boost at say 3k RPM and flooring it and wishing you had another 10 HP? I'd say the later fits my usage on track well on those rare corners that fall a bit out of 3rd's powerband, but are almost all too fast/short to think about 2nd in a 500 rwhp car.