this data from lyc 10360 A1B  turbo (normalized) charged,  ~ 200 hp
engine...)


Induction Air Temperature?



Gents:



What temperature rise do you typically see across your turbo?



[At my typical cruise of 16,500 or 17,500 I typically see IAT of about 177 F at 28.5" and 2550 RPM, flowing about 10 GPH.]



After putting the IAT probe in, I've observed the temperature on four flights.  Running at 25/25, the IAT is 160F to 170F, ~110F above ambient (50F to 60F), at 10,500 and 11,500.  Temperature drops at lower power settings, same altitude and external temperature.  I think I saw about 140F when I pulled the power back to21" in some turbulence.  That doesn't seem right - if the turbo is matched to the airflow, I think delta T should be mostly a function of the pressure rise and less so the work input (exhaust volume through turbo, which I assume would scale roughly 1:3 with intake flow), so I would not expect a significant temperature change with throttle position, only with altitude. Obviously I'm wrong.   An adiabatic rise would be ~65F to 95F depending on the controller setpoint. (That's 13" to 19" rise, for a setpoint of 32" to 38" Hg.)



[It's going to be more than adiabatic, 'cause the compressor is far from an ideally efficient machine. There have been two iterations now toward higher efficiency... first, TurboFlite started using a different compressor unit that was a bit more efficient at our operating point. And now TATI is considering using the same turbo that's used in the Cirrus install... an even more efficient unit.  As far as the throttle change correlation, remember that your increasing mass flow through the machine, and hence moving the turbine and compressors along their curves...]




Marc Wiese, 20B and 94 13B t engines