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It is not only a packaging problem, there is a fundamental physics problem that cannot be avoided. When power is produced by the front wheels they create a forc
by hristov 11y ago
It is not only a packaging problem, there is a fundamental physics problem that cannot be avoided. When power is produced by the front wheels they create a force between them and the ground. This is the force that causes the car to accelerate forward. But this force also puts pressure on the stickiness on the forward wheels and makes them want to slide.
If you apply a lot of torque you start getting microslides, or momentary losses of traction which reduce the front wheels ability to steer the car and cause torque steer and understeer.
A lot of the problems of oversteer you see in youtube videos and the like are really just very extreme cases. I doubt the Bolt, even with its electric motor, will have as much torque as a the souped up mustangs and corvettes that you usually see at those conventions.
In general, for the same amount of torque, oversteer is much better than understeer, because it does not cause nearly as much loss of steering (and the little loss it causes usually goes in the right direction, i.e., helping you turn). Oversteer is the result of the rear wheels sliding, and the rear wheels are not as crucial for steering as the front wheels. Thus microslides in the rear wheels will not cause such a loss of steering authority.
I remember i test drove a 200 hp front wheel drive audi, and it had noticeable understeer and torque steer problems. Then i test drove a 300 hp rear wheel drive infiniti, and it had no oversteer problems even though it had much more horsepower and torque.
Of course you can always cause dangerous situations with oversteer, but you need much more power and torque to do it.
- tadfisher 11y agoWhat you are saying, in simpler terms, is that the traction circle in FWD vehicles is limited by the fact that the same contact patch must handle both acceleration and steering. And that's true. This makes FWD setups prone to understeer. Everything you describe services this truth. What's not true is that torque-steer is caused by lots of torque overcoming available traction. The same torque is applied to both wheels in the absence of unequal-length half-shafts. You might induce understeer with the application of torque, but it will not induce a force which changes the steering angle moreso than the same understeer situation would induce on a RWD vehicle, and that's a function of the suspension setup, and mostly dependent on caster angle. Thus I submit that torque-steer is not an inherent flaw of FWD design, but of the most common packaging design in ICE vehicles. It's easy to conflate the two.