Originally Posted by
afterburner
Nice! Did it require a lot of material removal or modifications to get it to fit?
No removal, perfect fit. Had to epoxy the strap to the foam on the bottom - the lower neck on the bottle is perfect for the strap to hold the tank firmly in place.
I had to buy a bottle cap vent and fuel line attachment (Chief Aircraft) and quite surprisingly, it all came together with little effort. I made sure that I got the tank as close to the turbine as possible so that there would be minimal CG shift as fuel is burned off. My CG is around 175, far forward of the manual. I always measure CG in the landing configuration, landing gear down, header tank full, main tank empty.
I hit 145 mph on the telemetry GPS (tiny headwind) in a straight line at about 5/8 throttle. I am sure that if I pushed it at full throttle for a longer period, I would have confetti on my hands. A straight up line was just awesome and never ending. Power to weight is above 1.
The K85 (G2) is about the same size as the old K60 and it weighs about the same. I needed no weight in the nose; using a 2200 3S Lipo, 1300 3S Lipo, and a 2100 3S LiFe (turbine), upfront, brought the CG to where I wanted.