Thanks @Dan for your comprehensive comparison.
Thanks @Juozas for these speed data. I was going to ask you because you told me that you have a friend that flies one and you were just ahead of me 
Can you educate me, or us, on what the percentage power is for a few of these MP/RPM combinations? Or maybe some 915 owner can chime in..
Juozas wrote:
I have made my personal test with Bristell 915is RG MTOW 600kg.
Thank you! Still not quite as fast as the WT9, but these figures make more sense.
Do you have full aircraft pictures. T
Juozas wrote:
I have made my personal test with Bristell 915is RG MTOW 600kg. The figures are below. I have flown Dynamic WT9 RG 914 Turbo which has better fuell economy at the same speeds, however you can put 164 Ltr fuel tanks in Bristell to compensate the range.
This surprised me because if I fly at 9000 feet in my aircraft, I am typically flying 120KTAS, with the gear hanging out, whilst burning around 13 litres per hour. Here, with the same fuel burn, the RG 915iS is slower, with the added complexity of retractible gear? Ok, maybe the 915iS is designed to operate at higher fuel burns but this really surprised me, I would have expected it to be quicker, with the gear tucked away….
30kg, really? That is a huge useful load loss. The turbo on our 310HP TSIO520 Contisaurus looks out of a Mack truck and weighs, inclusive of wastegate, controller and overboost valve a total of 37.7…but that is pounds, not kgs. What is going on here?
Never believe what they write about useful loads in these sales materials. I bet this aircraft with the 915 in reality will weigh in right at 385 kg, or possibly more. Feel free to do your maths.
boscomantico wrote:
what they write about useful loads
Sorry, I was not clear: that was empty weight. Still cautious about sales vs actual data, but my point is why the 30kg gain because of the turbo system, which weighs so much less in my much bigger/heavier pressurized aircraft
I got that. But what it boils down to is still useful load.
Our B23T weighs about 20kgs more than our two B23s, at least it is roughly in that ballpark. But again, just sales material, and not real life numbers.
