Randy and Bob, thanks for the information, wow 245mph thats smoking, I am not sure who Fred tested with when he got the qm numbers of 224mph. That V-Vector was clocked in a dive with a Jett motor to get that 208mph reading, like you said, that ad did not help pylon racing in my opinion, we are of course much slower on the course... my own testing with my data recorder showed simular information that Randy stated in 428, The max I saw was 177mph, but I only dove it straight down for about 3 seconds, it scared me, thoughts of flutter, linkages and rods exploding kept creeping into my mind as I dove from high in the sky... I wish I knew how to make a better wood prop for those changes in atmospheric conditions... I am not quite sure what you are talking about when you discuss prop efficeincy, 82% is a good number, does it matter if it is because of drag and hp or actual prop slippage? The end result in speed loss is the same right? If I calcualte out prop diameter and pitch/rpm and the 80% efficiency rate, that should get me close to the speeds I can expect in the air??? The qm motors also unload close to 27k in the air, so a light prop that easily reaches 27k will accelerate better and reach top speed faster, but that top speed will be lower than a higher pitch prop that does not accelerate quite as fast, but reaches a higher top end straight away speed and reaches its 27k closer to the end of the starights... Thats my question, is it ideal to just reach top end speed right before you pull again, or is it better to reach the top end speed half way down the straight. Even though its slightly slower top end speed at half way in the straight, what is better, a little slower, but reached quicker or just reaching a higher top end speed just before you pull again??? That is what most of my testing has consisted of, testing lap times against different props that reach different speeds at different points on the course, and of course acceleration in and out of the turns...
JZW