Thanks, David!
This confirms that the TURBO 914 is probably the best matched engine for
this capable airframe.
Christoph
On 2014-09-22, 11:44 AM, "David Joyce" <davidjoyce@doctors.org.uk> wrote:
><davidjoyce@doctors.org.uk>
>
>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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