DYNO Numbers for Baggers???
I have seen in several places on the inter webs that HP Loss = (elevation x 0.03 x horsepower @ sea level)/1000. My brother who maths better than I do says that means that horsepower at sea level ={(1000×horsepower at elevation)÷(1000-0.03 elevation)}. Applying that formula to my horsepower and elevation means that my horsepower at sea level would be around 138, and at Detroit, MI it would be 135.54.
I like the sound of that. I am confident in the math part of it, but less confident in the underlying proposition regarding the effect of altitude. What do you all think?
https://wahiduddin.net/calc/calc_cf.htm
This calculator is simpler than the correction factor formula I found online, and it yields the same result. However, you might need to calculate some of the inputs. For example, my dyno sheet doesn't show the vapor pressure. I use this calculator to determine that:
https://www.weather.gov/epz/wxcalc_vaporpressure
and, of course, since that requires an input of the dew point, I had to calculate that, and did so here:
http://www.calculator.net/dew-point-calculator.html
The dyno sheet shows the temperature in degrees Fahrenheit (69.38) and the relative humidity (8%), which yielded a dew point of 5.5 degree Fahrenheit. That figure, in turn, gave me an actual vapor pressure of .06 in. of Hg. With that vapor pressure, and the actual pressure of 25.75, I was able to calculate the correction factor to be 1.153. That number, multiplied by the measured HP gave an SAE corrected HP of 137.69. If I understand all of this correctly, the corrected Torque figure would be 147.13.
Sure Hyper bikes make 180+ hp right from the factory and ours only make 80 something. But ask them how much torque they make. There is not a single Hyper bike that makes anywhere near as much torque as our bikes do.
Same thing with most of the others. That fancy BMW Bagger that everyone is going nuts over? 160 hp and 80 ft/lbs of tq. Don't get me wrong they are faster than out bikes, but not for the reasons you think.
Sure Hyper bikes make 180+ hp right from the factory and ours only make 80 something. But ask them how much torque they make. There is not a single Hyper bike that makes anywhere near as much torque as our bikes do.
Same thing with most of the others. That fancy BMW Bagger that everyone is going nuts over? 160 hp and 80 ft/lbs of tq. Don't get me wrong they are faster than out bikes, but not for the reasons you think.
Sure Hyper bikes make 180+ hp right from the factory and ours only make 80 something. But ask them how much torque they make. There is not a single Hyper bike that makes anywhere near as much torque as our bikes do.
Same thing with most of the others. That fancy BMW Bagger that everyone is going nuts over? 160 hp and 80 ft/lbs of tq. Don't get me wrong they are faster than out bikes, but not for the reasons you think.
https://www.bmwmotorcycles.com/en/mo...in-line-engine
Last edited by lightweight bob; Apr 2, 2018 at 02:43 PM. Reason: Additional info
The Best of Harley-Davidson for Lifelong Riders
https://www.bmwmotorcycles.com/en/mo...in-line-engine







Thanks.

