pic: 254/968 Gearbox - Destructive Testing Results

[Travis Covington]

Yes, torque is increased as the gear reduction increases... of course. I think I added a little too much there at the end with "transmission or otherwise" My ASSumptions were based on engine output torque, neglecting that fact that you have the ability to increase that torque in lower gears. Sorry.

I think the confusion here stems from my failing to explain that this rating I quoted is the "specification" value. Usually these horsepower and torque ratings are measured on an engine or vehicle dyno in a gear close to 1:1, or simply at the flywheel if on an engine dyno.

So no, this shaft wouldnt handle the torque at the wheels in 1st or 2nd gear on a honda civic. However, most people wont say their honda has a torque of 400 ft lbs because that is entirely dependent on the transmission and gear reduction, as you mentioned. And it would in fact be strong enough to handle the torque coming out of the engine.

I should read more carefully next time.


Also, I should add as I was somewhat upset by the other comment... we did do a cost analysis and mass production process and material selection. As the quantities get higher (very high), these gearboxes actually do have the ability to be cheaper than a steel alternative. Material costs become negligible, and the decreased machine run time and tool wear begin to make up for the costs added by anodizing and additional lightening. As manufacturing engineering students, we were far more concerned with these issues than we were the mechanical engineering based calculations.