Drivetrain loss & torque

[erlrich]

Dumb question; does drivetrain loss apply equally to torque as well as HP? Would you expect the % of loss to be the same?

[Ron Earp]

Earl, there is only torque being measured on a dyno (I assume you are asking with respect to dyno numbers). The hp is calculated from the measured torque. Therefore, if you assume a simple percent loss for the torque due to the drive train then this loss would also apply to hp.

HP = Torque * RPM / 5252

Torque is measured in foot-pounds for this equation to be correct.

Ron

[erlrich]

Thanks Ron - geez, if I had spent another 30 seconds thinking about it I probably would have realized that.

[GKR_17]

Earl, there is only torque being measured on a dyno (I assume you are asking with respect to dyno numbers). The hp is calculated from the measured torque. Therefore, if you assume a simple percent loss for the torque due to the drive train then this loss would also apply to hp.

HP = Torque * RPM / 5252

Torque is measured in foot-pounds for this equation to be correct.

Ron

Right on.

This is precisely why it's very near sighted to use a toruqe measurement to compare cars. HP through the useable RPM range is what matters.

Grafton

[JimLill]

HP through the usable RPM range is what matters.

AKA "power under the curve"