Transfer Case

[SLO_Scout]

I know that modern EVs, with their instant and linear “torque-curves”, do not need transfer cases per-se. I mean, the most capable EV off road rigs have direct-drive or at least direct-to-axle motors. With quad-motors and 1000lb/ft^2 of torque, transfer cases are not an option.

However, Scout will need to consider the need to flat-tow any off roader. Most EVs cannot do this without damaging the batteries and/or electronics. Please consider a way to decouple the motors from the axles/wheels. While transfer cases multiply torque at the wheels, they are also used to control wheel speed with the throttle. With no transmission, you could effectively spin the wheels at 80mph while at a standstill on sand, snow, and ice; not always a desirable characteristic.

You may also consider these benefits of a transfer case. If they are not necessary or cost effective (front and rear motors need two transfer cases), the benefits of controlling wheel speed in some conditions can be achieved by simulating gear reduction via throttle dynamics and other modifications in a driving mode.

 

[Ecca]

Please consider a way to decouple the motors from the axles/wheels.

How do you feel about classic manual locking hubs? The BOM cost would be super low and because a lot can be done in the software/electronics, it would only be for unusual edge cases.

 

[Jim Nichols]

Manual hubs at all 4 wheels for flat towing. I hope they do 2 motor solid axle front and rear. Wavetrac limited slip front and rear. What differential gear ratio would be optimal?

Wavetrac Differentials

Wavetrac limited slip torque biasing differentials.

wavetrac.net

 

[SLO_Scout]

Many dedicated trail rigs have 4 manual locking hubs in case they break an axle and need to drive home in front wheel drive. This is a good idea. Also, it is another nod to the old Scouts, with their Warn locking front hubs.

I assume that the Scout EV would be full-time 4WD. I think the hubs would be unnecessary and would remain engaged 99.9% of the time. I imagine that a circuit or relays could isolate the motors or a transmission having a neutral could alleviate the same issue. I guess SM’s fun will be in determining which way is cheapest and provides the right strength, reliability, and appeal to their market.

 

[MI Scout]

Manual hubs at all 4 wheels for flat towing. I hope they do 2 motor solid axle front and rear. Wavetrac limited slip front and rear. What differential gear ratio would be optimal?

Wavetrac Differentials

Wavetrac limited slip torque biasing differentials.

wavetrac.net

Wavetrac is the mechanical limited-slip differential I had installed on my BMW 135i back in 2011 and it still puts a smile on my face every time I drive it.

 

[Scout800a]

I actually think a 2 speed transmission would be ideal for the off road aspect of Scouts. Buuuuuut $$$ mean unless they make an offroad specific model that cost a lot more (like a Ford Raptor?) I don't see this happening for that reason.

And I would really love it if the made REAL locking differentials an option!

Current VW models (ID) have Neutral rolling mode so car can be pushed, pulled, go thru a car wash. I have no idea if the system can be left like that so car can be towed at speed. Probably going to be told to put it on a trailer. But I don't see why motor selection and some software couldn't make this a viable option on Scout.

Or maybe add a neutral position to the reduction transmission all electric vehicles have. Currently they are constant mesh and always in gear, but maybe that could be the economical option of allowing neutral for towing.

Jason

PS: And add a real Park Lock! Current models have no park lock, the car just applies the mechanical parking brake with an electrical motor.