Has anyone figured this out?

[22legit2quit]

I was thinking and I’m sure this has been posted somewhere on here, anyone figured out or are they working on being able to turn off one of the motors intermittently for extended range?

Seems like it would be somewhere to look for increased efficiency without a great deal of cost. I’d expect being able to put the front motor into a free spin potentially on the highway would be the best bet, it would be something like the MDS system that dodge used for the hemi, I realize that it wasn’t popular for an ICE but being that we’re in the business of actual efficiency I would think someone is close to figuring it out. Hopefully we can get a decent discussion going on this.

Sponsored

 

[TaxmanHog]

Been discussed before, which thread I can't remember, but NO it can't be done.
No disconnect of drive train available to permanent magnet motor means constant mechanical drag and induction of energy on the 3phase coils.

 

[22legit2quit]

Oh well, good thought I guess. No way to put one in neutral like you’d do for an automatic car wash?

 

[TaxmanHog]

Oh well, good thought I guess. No way to put one in neutral like you’d do for an automatic car wash?

slow rolling of the perm mag motor is not crucial a concern, but spinning it at 65+ MPH is......

 

[potato]

If it were possible, Ford would have done it. There would be an "Eco" drive mode and they'd be shouting from the rooftops about the increased range.

Same argument from decades past, with all the snake oil miracle gadgets to improve your gas mileage. If it were that easy, the factory would have done it.

Same with tariffs. But I digress

 

[Tony Burgh]

How does all wheel drive work? What locks the rear wheels together?
Are there locking hubs on each wheel?

 

[MountainAlive]

Rivian has something called “conserve mode” that disables the rear motor. If I understand correctly it mechanically / magnetically decouples the drive axles from the motor and power to that motor is shut off. Drivers say it adds about 15% range.

 

[TaxmanHog]

How does all wheel drive work? What locks the rear wheels together?
Are there locking hubs on each wheel?

The front and rear motor/axles remain independent but are electronically synchronized for rotation.

While the rear motor has an electro-mechanic servo that locks left & right pinions so that they won't turn regardless of slippage aka lock-up when you switch it on for off road driving.

 

[Henry Ford]

How does all wheel drive work? What locks the rear wheels together?
Are there locking hubs on each wheel?

The front wheels aren't connected to the back wheels by anything other than wires and software. Each axle has a drive motor and a differential like pretty much all gas powered vehicles. The differential allows the wheels to spin at different speeds, which is important for turning. The rear differential has the ability to be locked, which doesn't allow the wheels to spin at different speeds. This helps in certain off-road and low traction situations.

 

[123XYZ]

The front wheels aren't connected to the back wheels by anything other than wires and software. Each axle has a drive motor and a differential like pretty much all gas powered vehicles. The differential allows the wheels to spin at different speeds, which is important for turning. The rear differential has the ability to be locked, which doesn't allow the wheels to spin at different speeds. This helps in certain off-road and low traction situations.

Edited to add this spoiler: I am mistaken.

Unless I'm mistaken, front axles don't need or have differentials because they point in the direction of travel, even when turning, and absent some fancy 4-wheel steering setup, rear wheels don't do that while turning.

 

[Henry Ford]

Unless I'm mistaken, front axles don't need or have differentials because they point in the direction of travel, even when turning, and absent some fancy 4-wheel steering setup, rear wheels don't do that while turning.

I believe there is still a differential because the outside wheel travels a farther distance in a turn which means it spins faster than the inside wheel. No locker on the front axle of a Lightning.

 

[123XYZ]

I believe there is still a differential because the outside wheel travels a farther distance in a turn which means it spins faster than the inside wheel. No locker on the front axle of a Lightning.

Whoops! I'm more used to RWD and I guess I didn't think that all the way through. You're right. If the front wheels are powered, they need a differential too. I think the difference in distance traveled is smaller between the inside and outside front wheels than between the inside and outside rear wheels, but I'm not even sure about that. Dead (non-turning) axles don't need differentials because the wheels spin freely independent of the axle.

Sponsored