4 ms·
> I tune EFI systems on race cars as a hobby, and any car in the 8 second range usually needs to run slicks or drag radials to have enough traction. Right, but
by Florin_Andrei 9y ago
> I tune EFI systems on race cars as a hobby, and any car in the 8 second range usually needs to run slicks or drag radials to have enough traction.
Right, but you're comparing what is ultimately powered by the good old Karl Benz design from the 1880s, burning dinosaur juice, that has zero torque at zero RPM, needs to shift gears multiple times, and is about as responsive to control inputs as a cow munching on marijuana leaves - with a very different thing powered by something that has maximum torque at any RPM, has no gears, and responds to control inputs extremely quickly and with immense precision.
- rthomas6 9y agoEven if the difference was that drastic, none of that accounts for the fact that tires only have so much friction.
- Florin_Andrei 9y agoYeah. Nobody claimed that magic was at work here. Current tire technology has certain limits imposed by physics. But I suspect electric cars can get quite a bit closer to those limits, with a much faster traction control loop.
- Unklejoe 9y agoA couple of points: 1. A drag car does not start at zero RPM. The engine is probably over 4000 RPM and under load before the race even begins. In fact, many cars have to dial their launch RPM down because it ends up making enough power to lose traction from a dead stop. Look up "trans brake launch" to see what I'm talking about. 2. Your comment actually further confirms my skepticism of the Tesla not being able to maintain traction. If an unresponsive internal combustion engine powered car has trouble, imagine a car capable of shocking the tires even harder.
- Florin_Andrei 9y ago> A drag car does not start at zero RPM. I own a modern sportbike and I've done enough of quarter mile attempts to understand how the process works in general, even though it's not a 4-wheel vehicle. The main point here is that the internal combustion engine has a primitive torque profile. You have to keep it in the sweet spot if you want maximum performance. Hence all the stupid tricks you need to play with gear shifts and the clutch and all that junk. This whole coordinated ballet is unnecessary with electric motors, that's the point that you've missed. At any RPM, including zero, the electric motor is near peak torque. A whole range of complex issues that would otherwise need to be mitigated simply vanish, so you can focus on defeating other obstacles. Understand the difference now? > If an unresponsive internal combustion engine powered car has trouble, imagine a car capable of shocking the tires even harder. You're missing the point again. A much more responsive engine such as the electric power plant allows traction control to work much, much more precisely and respond much faster. No inertia from crankshaft assembly and transmission. No clutch. Torque goes from any value to any other value in a small fraction of a second. The feedback loop can operate that much faster, and with greater precision. Internal combustion engines are not even in the same ballpark. Like I've said, I do own a racing vehicle powered by internal combustion. I am quite fond and proud of it, which is something I believe you understand. But it's game over for this technology. Electric engines are winning by all metrics and in all applications, either sports, or utility, or whatever. It's the end of an era.
- bartvk 9y agoThanks for your explanation mentioning "coordinated ballet", only at this point the realization hit home how big the differences are.