Ragsf15e Posted November 16 Report Posted November 16 6 hours ago, Z W said: When we updated from a JPI EDM 930 to a G500Txi for engine monitoring, pretty much all the CHTs, EGTs, and especially TIT readings changed significantly. Of note, the TITs read significantly higher at the same power settings, I think, anyways. Fuel flow changed from being displayed on a Shaden digital fuel flow display to also being shown on the G500Txi, and we kept the factory manifold pressure and RPM gauges, and they always read slightly different than the new digital display. So the power settings are likely not exactly the same. My take away is that we're trying to measure with a level of precision never available nor intended by the designers of our 40+ year old engines. I think the probes in each customized installation may be in a slightly different spot and may come from different manufacturers. I keep this in mind when comparing my engine's performance to photos posted on the internet by others. Useful to compare but your mileage may vary (literally). Good points. One (not perfect) way is to compare airspeed between settings. Obviously dissimilar airplanes will be different, but they shouldn’t be grossly different from each other or book values at the same power.
Ragsf15e Posted November 16 Report Posted November 16 19 hours ago, Fix said: I've timed my mags several times with flower pot and digital meter and piston pin. Maybe I messed up, I've double checked it. At least both mags are even, maybe could try to adjust both mags 1 degree. At 29" 2300 RPM at 10.1g/h LOP I my TIT show just above 1550f on the analog gauge, most likley 1510-1560f range. Maybe it's higher than "normal", but on the other side it's still well below 1650f and also if the reading is "higher" even if the real TIT should be lower I have a margin to ~1600-1610f were my personal limit is. If I had a very low TIT with a functional TIT probe, then I might get above 1650f with out knowing it? On the Garmin G500, do you calibrate the TIT against the analog gauge or how does it work? I can also see that your EGT is lower than mine, what would be normal EGT temp? Is there any difference between JPI probes and Garmin Probes and the original Probes with read out? I totally agree that your tit value is plenty good where it’s at. I guess I was trying to think one step ahead but I didn’t articulate that…. At 10.1gph on a 220hp SB engine you’re running about 60% power (62.8%). And that’s fine (and very efficient). However, it’s nice to be able to crank it up to say 70% or maybe even higher still LOP and take some extra knots when you want to. I suspect if you run 11.2gph for 70% (increasing the mp to stay LOP), the tit is going to start getting uncomfortably high. I bet the new gami injectors will help though. Your spread is better than mine now, and mine seems to run great lop up to at least 70%.
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