Setting Red Cube K-Factor
I just installed a new to me Dynon EMS D-10 and have started flying with it. On first flight, the fuel flow was wildly inaccurate so, I checked the K-factor at it had somehow gotten set to 30,000. I set it to 68,000 and it was in the ballpark. I really don't do any cross country with our 8 so I wanted some way to set the flow as accurately as possible without flying hours and hours to compare actual burn to recorded burn. I found an app called Aircraft Power which allows you to select the engine, altitude, manifold pressure and temperature. Once the parameters are set, it will tell you the exact horsepower being produced (leaned to best power or 50 degrees rich of peak). Once you have that number, you can go to the Lycoming Operators Manual and using the chart shown below, you can determine the fuel flow in pounds per hour which is easily converted to gallons per hour. So, I just selected 3,500 feet, 20 inches of MP, 2400 RPM and 41 degrees OAT and the app said I would be producing 116 horsepower on my IO-360 A series engine (angle valve). The Lycoming chart said I should be burning 10 gal/hr when producing that horsepower. I then flew the airplane, set those exact parameters and while the Dynon was close, I was able to dial it in exactly in a matter of minutes by adjusting the K-factor while in-flight. Time will tell just how close I was able to get it but it seems like an easy, quick way to set the K-Factor. I would appreciate other eyes looking over my calculations and making any suggestions.
Last edited by 74-07 : 01-29-2022 at 11:02 AM.