kearney
Well Known Member
Hi
Yesterday I decided to collect a little real world data flying behind the SDSEFI.COM Electronic fuel injection / electronic ignition.
To start I have been tuning my ECU maps so that I don't need to touch the mixture knob. I have set the maps so that at altitude the engine is running close to best power / stoichiometric. When I flip the magic LOP switch, I set it so that the spark is advanced by 6 degrees and the engine is leaned by 8% or so. I was shooting to be running LOP by 40 - 50 degrees.
The table below shows the results. The data was collected when it was a bit bumpy at lower altitudes but directionally it seems consistent with what I was shooting for. The spark advance seems to have offset the power loss I would have otherwise seen as I reduce fuel flow.
I do like being able to tweak the engine in flight!
My apologies for the poorly formatted table - I couldn't sort out how to make it presentable when posting.
Norm LOP
Avg Avg
Alt MP RPM OAT FF TAS CHT MPG FF TAS CHT MPG %
10000 21.1 2390 27 12.5 167 348 13.36 11.6 162 341 13.97 0.05
12000 19.8 2390 17 12.4 165 347 13.31 11.4 168 346 14.74 0.11
14000 18.3 2390 8 11.8 161 352 13.64 10.7 164 338 15.33 0.12
16000 16.8 2390 -2 11.2 156 339 13.93 10.5 163 328 15.52 0.11
18000 15.5 2390 -12 10.5 159 327 15.14 9.9 160 325 16.16 0.07
Yesterday I decided to collect a little real world data flying behind the SDSEFI.COM Electronic fuel injection / electronic ignition.
To start I have been tuning my ECU maps so that I don't need to touch the mixture knob. I have set the maps so that at altitude the engine is running close to best power / stoichiometric. When I flip the magic LOP switch, I set it so that the spark is advanced by 6 degrees and the engine is leaned by 8% or so. I was shooting to be running LOP by 40 - 50 degrees.
The table below shows the results. The data was collected when it was a bit bumpy at lower altitudes but directionally it seems consistent with what I was shooting for. The spark advance seems to have offset the power loss I would have otherwise seen as I reduce fuel flow.
I do like being able to tweak the engine in flight!
My apologies for the poorly formatted table - I couldn't sort out how to make it presentable when posting.
Norm LOP
Avg Avg
Alt MP RPM OAT FF TAS CHT MPG FF TAS CHT MPG %
10000 21.1 2390 27 12.5 167 348 13.36 11.6 162 341 13.97 0.05
12000 19.8 2390 17 12.4 165 347 13.31 11.4 168 346 14.74 0.11
14000 18.3 2390 8 11.8 161 352 13.64 10.7 164 338 15.33 0.12
16000 16.8 2390 -2 11.2 156 339 13.93 10.5 163 328 15.52 0.11
18000 15.5 2390 -12 10.5 159 327 15.14 9.9 160 325 16.16 0.07
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