Friction is non-linear so you're going to need very fast feedback loops on the brakes to simulate a locked differential. One can't just apply a fixed amount of braking to every wheel and have stuff magically work out.
Yes. On normal cars this is achieves by sensors and brakes that I believe work at 100 times a second and up. Tesla have the advantage that they have similar control over acceleration. This technology has been common for years, and early on it had lots of downsides, but it's most recent versions is quite good. It's becoming more and more popular, even on enthusiast cars.
The main issue is while limited slip differentials do work, they are expensive, add weight, and they add friction. So the software solution gets you better MPG, better HP, and more control. There's many different names for it, traction control, torque vectoring, traction assist, etc.
Even Subaru who bet the heaviest on AWD (selling only AWD until they sold the BRZ), and had one of the best respected AWD systems is moving to open differential with the brake assist, on at least some of their cars. Not sure about the STI and WRX though.
Thanks! My side hobby is restoring & retrofitting 80s vehicles, so I had not considered new tech like this. I just assumed it worked like every other open diff.
That's how every other open-diff car already works. Everyone does that. EVs just have the extra advantage that they're much more precise at applying power so the traction control can be much better.
That's also what I mean of course. All modern AWD systems and even just FWD/RWD cars use the ABS to do traction control with open-diffs. The base AWD system in a Subaru is three open-diffs and then ABS braking is used on any wheel that's slipping to make sure the torque still reaches the other wheels.
Right, as I mentioned, I'm an 80's VW van enthusiast. I've transplanted subaru engines into VW vans, but I always clip the unused sensors (like traction control) from the wiring harness. I haven't touched anything newer than 2005 yet.
So, despite "everyone doing it" by your words, I was just unaware of how it worked because it's not relevant to me. My VW syncro van has both forward and rear locking differentials anyway.
