I drove such a a car for many years-an Infiniti G20t. There was minimal torque steer with that car. It didn't have a lot of horsepower (135hp to the wheels) though. My understanding at the time was that Nissan used unequal half shafts to minimize torque steer.

If you've ever watched high powered FWD cars (300+hp) drag race, you can see immediately the disadvantage of not having an LSD-they call it the "one legged dance".

 

I don't think that a LSD ensures that both shafts are always spinning at the same speed. If that was true, a LSD would not be much of a differential.

Find an old Cadillac Eldorado, with its 8.2L V8.

 

SUVs that are designed from the get-go for sporting off-road use are likely to have a front lockable front diff'l and maybe a front LSD.

To have a mechanical LSD or even a differentially acting "virtual" one using the brakes would put too many inexperienced driver's fingers and thumbs at risk due to QUICK, STRONG and SOLID/FORCEFUL torque stear.

Most, if not all, FWD traction control systems will attempt to alleviate wheelspin/slip via braking of both front wheels simultaneous even with only one slipping. Otherwise you might experience some rather severe torque stear, enough to yank the stearing wheel from your grip, or ever break a thumb or finger(s).

 

The definition of RSC ( rollover stability control ) that everyone is drueling at the mouth to have... is the ability of the computer to brake each wheel individually.

 

True. Plus, ABS, TC, and RSC can't change the laws of physics, nor create additional traction. It can just attempt to better manage what little is available.

For example, if you are heading straight for a concrete wall, you might try to quckly turn away. However, if you turn too sharply, and the RSC detects a likely roll-over, it will attempt to abort the turn (lock a front wheel to intentially cause understeer/plow). Of course, without the turn, you now hit the concrete wall. But your last thoughts will be satisfaction that you didn't roll-over instead.

 

I think there is some confusion here between LSDs that performance oriented FWD cars have had for many years and lockable diffs that are designed for low speed 4x4 use. The mechanical LSDs on FWD vehicles are much like 'posi-traction' on older RWD cars. They do allow different wheel speeds for safe,controlled acceleration when turning or on slippery surfaces. Some production FWD cars have 250+hp, and they employ a variety of methods to accelerate predictably.

I've never heard of a lockable front diff on a FWD car, but maybe someone here knows of an example?

 

My point was, I think the worries about "torque steer" are getting blown way out of proportion here.

Broken or even hurt fingers? C'mon. This is not your fathers Oldsmobile!
Power steering with hydraulics allows very little driver input force to apply a large amount of turning force. You can turn a heavy car sharply with 1 finger on the wheel.

So it follows to me, that a large amount force via unequal torque on the left and right side, would also transfer very little force back to the steering wheel.

 

Interesting concept, but the opposite of what will actually occur. A car without skid control is more likely to skid into the wall. The one with skid control will tend to maintain directional stability away from the wall.

Heading for a wall and yanking the wheel causes understeer (plow) or oversteer (tail slides out and rollover becomes possible), both of which are a traction loss. Without traction, momentum pushes you toward the wall. Incidentally, this is why most vehicle suspensions are tuned toward understeer. Understeer is the safer alternative to a tail slide since those are hard for the everage driver to control and can lead to rollover. Stability control will mitigate the plow or slide by instantly modulating forces in such a way as to change weight distribution such that the tire with the most traction gets more braking force while those skidding are modulated to stop their slide. The end result is that the car regains traction much more quickly than it otherwise would, keeping it turning in the direction the steering wheel is pointed. Presumably, that is away from the wall.

It's absolutely true that stability control can't find traction where none exists. But, like ABS, it can apply braking at a rate and in a way that is not humanly possible. Additionally, it can regain lost traction significantly faster by modulating forces at the four contact patches independently. This redistribution of forces causes a redistribution of weight, rotation, and so on. This is what you need to change a skidding situation into a turning situation.

 

When I turn on DSC on my Mini S and go around a rotary in the rain, I can floor it and the car will go around the rotary at a faster rate than I could without it. What DSC can offer is a few moments in time to change something that without it could not be done. If you do nothing, the accident is still going to happen. And in some cases if you are being a complete idiot, the accident is going to happen regardless of what your car has. I don't know how this thread went to DSC instead of LSD.

 

The brick wall.

We're forgeting about intentional overstear.....

VSC would do its very best to PREVENT your entry into the region of overstear therefore in that case, were you relying on a bit of overstear, meet the brick wall.