Addressing torque steer?

[Tony Burgh]

And here I thought Ford built the Lightning for truck people to do truck things (like In the picture).

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[Heliian]

And here I thought Ford built the Lightning for truck people to do truck things (like In the picture).

I read somewhere that the lightning is attracting more non truck people than any other truck out there.

 

[TaxmanHog]

ALL my former F series trucks 150/250 were RWD only, I've been compensating my launch while turning technique as well, you're not alone

 

[Tony Burgh]

I read somewhere that the lightning is attracting more non truck people than any other truck out there.

Readily apparent by some of the comments and questions we see on this board. When sincerely asked, many jump in to answer.

 

[data003]

The motors have the same rating, but that’s not really relevant in this context. The power control system can bias the power distribution to either front or rear.

It would be super awesome if Ford let us adjust this… I’d love to get the rear end looser in the snow.

 

[eRockBoon]

Is the torque steer issue not just a problem of the vehicle having a 50-50 weight distribution? It seems to me when you step on the accelerator, all of the weight shifts to the rear of the truck, which gives the rear tires much more traction. Then one of the two front tires will start to spin as it will no longer have as much traction. The traction control system, then redirect torque to the other front wheel, which intern causes it to spin and the cycle continues back-and-forth until the vehicle is able to readjust the weight evenly between the front and back and left and right tires so that they all have equal amount of traction.

This wouldn’t occur in an internal combustion engine vehicle because you have the heavy engine above the front wheels, meaning that your front wheels will always have more traction than your rear wheels even when under heavy acceleration.

Perhaps I’m thinking about this all wrong. I’m definitely not an engineer, nor a physicist, simply a biochemist.

 

[Tony Burgh]

Perhaps I’m thinking about this all wrong. I’m definitely not an engineer, nor a physicist, simply a biochemist.

Stick to your Krebs cycle and leave the mechanics to the engineers.
The nanny stability and traction controls are always compared to perfection. If you’ve ever 4 wheel drifted a 73 Ford pickup into a bend at 70 mph and said 3 Hail Marys and a Glory Be for the truck to regain traction, you’re eternally grateful for traction and stability control.

 

[eRockBoon]

Stick to your Krebs cycle and leave the mechanics to the engineers.
The nanny stability and traction controls are always compared to perfection. If you’ve ever 4 wheel drifted a 73 Ford pickup into a bend at 70 mph and said 3 Hail Marys and a Glory Be for the truck to regain traction, you’re eternally grateful for traction and stability control.

Yes, traction control is great but I suspect it is also what is causing torque steer under strong acceleration.

 

[Tony Burgh]

Yes, traction control is great but I suspect it is also what is causing torque steer under strong acceleration.

Torque forces affect all four wheels, whether awd or 4wd. But rear wheels are braced to not turn left or right so no torque steer. The front wheels? They are just doing their job and when steering force is applied by the driver or motion of the accelerating spinning wheel.
Traction control reduces the acceleration forces on the wheel by slowing it down.
Now the disclaimer: I’m a ChemE. Statics and dynamics was a chore.

 

[GDN]

This has been discussed a few things and it seems a bit disturbing. No engineer here either, but I am a judge of engineers and I have no belief that Ford can't do better than this. They can do better than this, or at least SHOULD be able to do better than this. You won't get this out of a Tesla. I won't pretend there aren't differences and this is a truck, but you get such an incredible straight line launch from the Tesla.

 

[Amps]

you get such an incredible straight line launch from the Tesla.

You get pretty good straight-line launches out of Lightning, too. But, you'd better hold on to that wheel when making launching into a turn from a stop or it will straighten right out.

I think it may have something to do with using identical PM motors and trying to match their outputs fairly closely for efficiency. You don't want too much push-me/pull-you motor/generator stuff going on in an EV. That's what you get, unless you have one induction motor (like the cars mentioned), or a method to physically disengage one of the PM motors from the wheels.

 

[Adventureboy]

I mean I'm not here to brag but it's remarkably more frightening compared to any Telsa, Porsche, STI, etc that I've owned or driven. It gets away from you very quickly.

Remarkably more power, traction, and weight than any Tesla, Porsche, STI etc. I have a high-pressure turbo Volvo S60 FWD and it is far worse than the Lightning for torque steering. It is a function of the differential in the front (ie. it turns the easiest wheel first). It can be solved by putting dual hub motors on each wheel rather than a single motor with a differential. Maybe they'll do that on the T3.

 

[VTbuckeye]

You get pretty good straight-line launches out of Lightning, too. But, you'd better hold on to that wheel when making launching into a turn from a stop or it will straighten right out.

I think it may have something to do with using identical PM motors and trying to match their outputs fairly closely for efficiency. You don't want too much push-me/pull-you motor/generator stuff going on in an EV. That's what you get, unless you have one induction motor (like the cars mentioned), or a method to physically disengage one of the PM motors from the wheels.

Not a permanent magnet motor issue. I tried it this morning in our xc40 EV (402 HP, 486 ftlb torque. Two permanent magnet motors). Launches without any torque steer. With the lightning it may have to do with tires/suspension. The power train tuning of the Volvo is much better than the ford (light throttle/regeneration switch over is absolutely seamless in the Volvo). There is also a slight ramp up of power, so it isn't there all at once.

 

[GDN]

I know you don't want any braking if your goal is to get off the line, but if it is due to they way they put the power down, they can always get a little braking action on the opposite wheel.

I'm not sure I believe any of that though. Again, not an engineer, but I think they are just too lazy to figure it out and use the motors and technology to firmly apply the best power they can where it is needed and not cause the torque steer like they do. I won't argue it any more however until we see what the Cybertruck does against the T3. Then we'll compare pure engineering and control.

 

[Adventureboy]

I guess what I'm saying is that the Telsa Model S/Model 3, 911 Turbo S, and STI that I have owned/driven are AWD. Granted some of them have a RWD bias but so does the truck.

I'll try off-road mode.

To my knowledge, Off-Road mode only locks the rear differential, not the front. Has anyone tested this?

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