Christopher, Although not directly comparable, you may be
interested in the following figures for my XS mono G-XSDJ
with 914, Woodcomp SR3000/3/W, Smart controller and speed
kit at 90% MAUW and 2000 ft unless stated otherwise:
Max speed at 100% power (ie not using the extra 15%
available for 5 mins only) TAS 156kts (164 at 6500ft)
Fuel flow:
100kts 12 l/hr
110 13
120 14
130 19
140 23
At 10,000ft 150kts TAS (129kts IAS) 21 l/hr
These figures came from a comparison I did between the low
twist Sr2000 prop and the high twist SR 3000W prop, which
showed the latter gave appreciably better performance with
max speed being 4kts higher at various altitudes, fuel
flow being on average 0.6 l/hr better, climb rate improved
and cooling problems transformed. The increased top speed
according to CAFE calculations was the equivalent of
having an extra 4 hp!
Regards, David Joyce, G-XSDJ
Christoph Both <christoph.both@acadiau.ca> wrote:
> Dear Europa Community:
> I thought you might find the following comments and
>attached spreadsheet of interest.
> I tested and tabulated fly data for Canadian C-GPEL on
>SEPT 17-2014. You might be interested to see where the
>most gain is for C-GPEL Classic 912S, Woodcomp 3000 two
>blade propellor, Smart Avionic Prop Control. The data
>collected, for 4950RPM where possible, is denoted
>separately for fuel efficiency and speed with a linear
>increase in MAP from minimum required power to keep the
>plane at altitude, all the way to WOT, measured at 2500
>feet. There are some interesting jumps in the graphic
>curves, most noticeable around the (EGT) point, where all
>4 cylinders turned out to be exactly the same EGT within
>10 degrees Celsius on a GRT graphic analyzer (meaning:
>most effective combustion=best torque). So for most
>efficiently butting into headwind best suggested would be
>27.5MAP (115 IAS) while most efficient tailwind use
>would suggest 24.5MAP (95 IAS) or even 23.5 MAP (91 IAS)
>with a fuel burn of only 9.4 litres/hour (or 2.5 GAL/hr)
>exactly as the book says. Endurance can be chosen at
>22.5MAP with a fuel flow of only 8.1 litres/hr (2.16
>GAL/hr), magically arriving at 87 IAS, empirically found
>to be the most efficient climb speed. Quite a magic
>square this little airplane. This is all without any
>speed kit or wheel pants.
> Chris
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