"Jim Macklin" wrote in message
...
Very true. On a turbocharged airplane the EGT is calibrated
and called a TIT [an a jet it is ITT or TPT]
The turbo has designed temperature limits and because it is
rotating at 35,000 to 120,000 rpm it needs very good
strength to stay in one piece. It also needs to be cooled
at a moderate idle speed for 4-5 minutes to allow it to
spool down, cool off and have good oil pressure. A closed
throttle idle doesn't supply enough oil volume to cool the
turn bearing, and a fast idle, particularly a simple fixed
waste gate type won't let it slow down enough.

Bottom line, RTFM for the particular model and serial
number.

John's airplane, a Cessna 340, came from the factory with an EGT (when
installed), not TIT. EGT is located forward of the turbo and actually has a
higher temperature than the TIT. Some airplanes, such as the P-Baron and
58TC have TIT, the probe is actually located in the turbo inlet. I was just
commenting to John that I have never seen RAM recommend any particular EGT,
only the 1650 degree max. I agree with the rest of your post.

Allen