# Calculate car acceleration from torque

I have data:

mass = 740 kg
wheel diameter = 670 mm
Rw = 0,335 m
power (max?) = 750 horsepower (551kW)


Now I would like to calculate car acceleration when throttle is max and speed in this moment = 100 km/h = 27,78 m/s

I calculate wheel RPM from this:

wheel speed(RPM) = v(km / h) * 25 / (3 * pi * r(m))


I get

WHEELrpm = 100 * 25 / (3 * 3,14 * 0,335) = 792


Next I calculate engine rpm:

RPMengine = RPMwheel * idifferential * igearbox * iclutch


where:

iidifferential  = 3,42
iclutch = 1
igearbox (gearbox ratio) = 2,55

RPMengine = 792 * 3,42 * 2,55 *1 = 6907


next I calculate torque from:

torque = (POWER * 5252) / rpm


I get

torque = (750 * 5252) / 6907 = 570


And now, apart from the resistance, I want to calculate drive force and acceleration.

I found this:

Fdrive = torque * gearboxRatio * iidifferential  * n / Rw
n - transmission efficiency (0,7?)


But I wonder if I can use it considering previous calculations. How to correctly calculate the acceleration now?

I try to base on this: https://engineering.stackexchange.com/a/22021 but I dont understand this formulas

• acceleration is a change of velocity but you fixed that at 100km/h Jun 19 '20 at 15:04
• I mean this is speed at this specific moment of time Jun 19 '20 at 15:14