Torque through driveline losses
No one has answered the question I asked yet! If my motor puts out 530ft lbs at the back wheels what would it likely put out at the flywheel?
As said, net torque is going to track HP losses. So the 15-18-20% numbers should apply.
530 ft-lbs at each axle? If that was the case, then you have to know the transmission gear used for measurement , the rear gear, and the approximate efficiency loss. OR, if the dyno 'translated' the torque to top gear (4th gear) numbers.
Assuming it translated the results to top gear: If you had 530 ft lbs at each axle (both tires biting well so the torque out of the rear gear splits equally) for a total rear axle torque of 1060 ft lbs , a 3.91 rear gear, and were in top gear (1:1 gearing in the trans) with a 15% efficiency loss, I do believe that would work out to around 319 ft lbs at the flywheel.... which seems low. With a 25% total efficiency loss, then the flywheel numbers rises to 361 ft lbs.
But, I do not know in what format that dyno gives you a wheel torque number. Does it account for tire size, and account for gearing? Is it torque per axle or total? Is the torque on the rolling drum or the vehicle axle? (If that 530 number was the total for the rear axle, then the number at the flywheel would drop in half of what I show, and that does not seem right. So it seems correct to assume their dyno number is per wheel.)
Do you have dyno sheet that might show the input info? (Like, trans type and tire size?) Did you make 'runs' on the dyno, or measure at steady state RPM's?
