Al,
Good point on the calibration. No, I'm still working on that. But it has taken a backseat to the MAP table issues. Currently the fuel burn is registering high, resulting in a fuel remaining reading lower than what I actually have in the tanks. I hadn't made the connection between that and the GPH reading, but now I see that they are inter-related. I usually don't fill the tanks to the brim as I can carry 96 gallons total but I only fly about 100-150 miles round trip. Why carry all that extra weight? So, I rely on my capacitive gauges to determine total fuel and fuel used, and then compare that to the fuel remaining reading on the EM-2. Usually the EM-2 reads lower than the fuel gauges which, if I understand correctly, would indicate that the GPH reading is higher than it should be (that's good news). I obviously need to adjust the fuel flow calibration a bit.
Also, I can't say whether my EM-2 is in mph or kts. Going by that, it is likely in mph, but I'll have to verify that also. That might shed some light on why the EFIS airspeed is lower than the EM-2. More things to do next weekend, and another reason to go fly.
Mark
On Mon, Sep 8, 2008 at 6:58 PM, Al Gietzen
<ALVentures@cox.net> wrote:
The real "jewel" has been the c/s
prop. This allows me to cruise at around 10.6 gph at 4200-4500 rpm, 153
TAS. Until recently, I had been cruising at 5200 rpm, burning 14-15
gph. Speeds are about the same.
Mark
Hi; Mark,
Is your fuel burn pretty accurately
calibrated? My gallons used readout is still about 5% high, so my burn
would be likewise. I typically cruise my 20B at about 5400 - 5500 rpm, MAP
aprox. 18" at 7500' and get 9.3-9.5 gph when running 50-80F LOP.
I expect the MAP readouts may differ a bit as I found I had to change the
calibration on mine to get a correct reading.
TAS reported is calculated by the EM-2 and is in kts.
My EM2 reads out mph. I guess you
changed the calibration factor. Also the TAS is about 5% higher than the
GRT EFIS readout.
Best,
Al