Gregski wrote: ↑Fri Dec 15, 2023 4:09 pm
both of my pulls were done from rolling starts, the first one from almost 40 miles per hour, and then I think it held for about 10 miles till 50, and yeah I am using a very small 9 kWh hybrid battery pack, one that I shouldn't even be running around with let alone driven 25 miles to a dyno shop and then tried to do some power pulls, lol
also both of my graphs are just horse power, one is from almost 40 miles per hour the other from about 10 mph
HP Curve.jpg
HP Curve 2.jpg
Ahha your 10mph pull looks much more like i'd expect! You can see the constant torque region now.
If we know tyre size we can calculate wheel torque from the chart.
Your 215/65r17 tyre has a diameter of around 28"/711mm and will do around 721 revs per mile.
At 20mph therefore the wheel is doing (721*20/60) 240rpm.
Its making ~73hp at 20mph/240rpm so we know its making 1597lbft at the tyre. (Power*5252/rpm)
At 30mph its making 110hp, doing the same math we can see that again its making similar torque (1604lbft)
Thereafter it transitions into power limiting and torque starts to fall off.
We also know your rear diff ratio, 3.73 and the 1.9 reduction in the trans, so we can calculate motor torque.
1575/3.73/1.9 gives us around 222lbft, or almost exactly 300nm at the motor.