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Nimisys · 03-28-2005, 06:56 PM

well it could be game devs playing engineer in an areana they do not know all that well

or it maybe they are using gear reduction in the wheel pods, a la the H1 and its 2:1 reduction in the gear hubs. multiple speed hubs could be a reasonable argument for the difference in tone. BTW this is how deisel locomotives, heavy equipment function, diesel engines powering electric generators powering electric motors at the wheels.

BTW torque calaculations:
Power (hp) = Torque (ft-lb) * RPM / 5252
as well as:
Power (hp) = Force (lb) * Velocity (MPH) / 374
463 = X * 48.5 /374
Force = 3570lb at peak velocity.

However that number will be different than at the engine in a normal vehicle because it does not take into account gear ratios in the trnasmission and final drive units. furthermore in this example the engine output can not be derived based on the performance of the electrics as we lack any gear reduction data as well as the effiency data of both of the eletric motors and generators. furtheremore with an electric motor peak torque is avilable at zero rpm. assuming we ignore this, and base torque off of a HP reading of 463hp @ 5000 RPM, then we can calculate the torque at 5000 rpm.

Power (hp) = Torque (ft-lb) * RPM / 5252
463hp = X * 5000 / 5252
X = 486.33 ft-lb @ 5000rpm

This is why dyno charts display both torque and HP as a function of RPM.

so 486.33 ft-lbs at the engine and 3570 ft-lbs at the wheels indicates a 7.34:1 reduction at 5000rpm. thats roughly equivalent to 2nd gear in most 5 speed vehicles with a mid 3.x:1 final drive.

03-28-2005, 06:56 PM	#12 (permalink)
Nimisys Crazy Location: San Diego	well it could be game devs playing engineer in an areana they do not know all that well or it maybe they are using gear reduction in the wheel pods, a la the H1 and its 2:1 reduction in the gear hubs. multiple speed hubs could be a reasonable argument for the difference in tone. BTW this is how deisel locomotives, heavy equipment function, diesel engines powering electric generators powering electric motors at the wheels. BTW torque calaculations: Power (hp) = Torque (ft-lb) * RPM / 5252 as well as: Power (hp) = Force (lb) * Velocity (MPH) / 374 463 = X * 48.5 /374 Force = 3570lb at peak velocity. However that number will be different than at the engine in a normal vehicle because it does not take into account gear ratios in the trnasmission and final drive units. furthermore in this example the engine output can not be derived based on the performance of the electrics as we lack any gear reduction data as well as the effiency data of both of the eletric motors and generators. furtheremore with an electric motor peak torque is avilable at zero rpm. assuming we ignore this, and base torque off of a HP reading of 463hp @ 5000 RPM, then we can calculate the torque at 5000 rpm. Power (hp) = Torque (ft-lb) * RPM / 5252 463hp = X * 5000 / 5252 X = 486.33 ft-lb @ 5000rpm This is why dyno charts display both torque and HP as a function of RPM. so 486.33 ft-lbs at the engine and 3570 ft-lbs at the wheels indicates a 7.34:1 reduction at 5000rpm. thats roughly equivalent to 2nd gear in most 5 speed vehicles with a mid 3.x:1 final drive. Last edited by Nimisys; 03-28-2005 at 07:04 PM..