created June 12, 2015
I took this during a "cuise speed" test. Although you wouldn't know it from the altitude or GPS altitude display, the density altitude (also displayed) was 7535' which is in the range of 75% engine performance. True airspeed (shown as TAS) was 155mph. Disregard the -50fpm descent rate...it was steady-state level, but the iEFIS jumps all over the place. It could just as easily read -150fpm!
This was wide open throttle, which burns way more fuel than when throttled back to 3350 rpm, which is doing about 145 mph and about 4.0 gph rather than the 5.3gph shown. That nice fuel economy is a fine trade-off for 10 mph of airspeed. This run was without a spinner, which slows it down by about 2 mph. Down low and wide open, top speed is in the high 160's range, pushing 170mph.
After looking at this picture I noticed the CHT on cylinder #4 was missing. It took about five seconds after the cowling was removed to find that I had a broken head stud, which is where the CHT probe had located (under the nut). The probe runs pretty cool when fed 67F outside air! The main reason I pulled the cowl was to install a current sensor to fix the goofy Amps display. I'll have plenty of time for that now!
More later...
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