Rogue_Ant

Shock is what breaks the drivetrain.
The stock 951 trans can hold plenty of toque, as long as its application is smooth.


-Rogue

Robin W.

Are you breaking the tires loose as you release the clutch? Or can you break them loose on demand just with the gas pedal? For the most part the car will stay in 2nd or 3rd gear only, they behave quite the opposite to gas engines, max torque is at low rpm (0 and up), but they have a nice power band because peak power is at higher rpm just like a gas engine, but peak efficiency is also at high rpm so when cruising down the highway I want it to run between 4k and 5k vs a gas engine where you either want to keep the rpm a bit lower.

Rogue, thanks for the input. I think the rapid application of torque would be shock you are refering to, I'll just have to keep the controller settings a little tame so it ramps the current up at a slower rate to avoid breaking things.
With the harshest controller settings I could apply 300+ ft-lbs to the tranny before the tires start to turn.

V2Rocket_aka944, the main point of the different gear ratios is torque multiplication so make the best use of the available torque/power from the motor. To create the same thing I could simply leave the tranny in 5th gear and regardless of speed I would have 400ft-lbs available. (The electric motor can start from stall speed and would accelerate the car very slowly from a dead stop in 5th gear)
Once you add in the rear diff ratio into your tranny ratios, 1st gear with 24" dia tires (to make the math simple) would put 4700ft-lbs to the road, or ~1.5G acceleration but I know the suspension/tires couldn't hold this.

That's why I plan to start in 2nd gear because 300ft-lbs x 3.38 x 2.059 = 2087ft-lbs (if I had 24" dia tires, I believe they are a bit larger so the torque decreases accordingly) but for easy math 2000ft-lbs in a 3000lb car gives you an acceleration rate of .66G's which is fairly quick.