[mrbrowning]

I’m a committed manual driver, but I fully grant that dual-clutch transmissions and EV powertrains handily outclass manual transmissions from the perspective of effectiveness (although my casual understanding is that an electric motor without a gearbox is still going to be limited in its ability to provide torque at high rotor speeds). I would consider driving a car relying on either of those technologies, even though I favor the subjective experience of a manual transmission, but I still can’t imagine driving any vehicle with a torque converter or a CVT (CVTs sound great in theory, but as far as I know they’re still pretty limited in terms of torque tolerance). I’ve driven some nice autos and still find their response to torque demand from the pedal to be unacceptably slow, plus I find the way that throttle mapping works in manual transmission cars to be much more intuitively close to what I would expect from direct throttle control. Flooring it to induce a downshift feels like a crude distortion of the input space in a way that inhibits the development of an intuitive connection with the vehicle’s operation.

Anyway, if you’re a performance vehicle enthusiast on a budget, you’re going to have trouble finding a suitable car that isn’t equipped with a manual.

[Diederich]

> although my casual understanding is that an electric motor without a gearbox is still going to be limited in its ability to provide torque at high rotor speeds

BTW I find your entire comment pretty interesting.

So the current top speed on Tesla Models S3X is 155MPH. The Roadster 2 is expected to have a top speed of 250MPH.

Is the 155MPH an example of what you're referencing Re: high rotor speed? Thanks.

[mrbrowning]

Less top speed, which is governed by many factors (consider that maintaining any constant speed in a vehicle requires some minimum power output to counter losses to heat/friction throughout the drivetrain and between the vehicle and oncoming air, not to mention the maximum safe operating speed of the drivetrain components themselves), but rather the potential for acceleration. If you look at the torque curve for some power plant, where the independent variable is oscillation speed and the dependent variable is output torque, you'll find that (for some fixed gear ratio between the power plant speed and the wheel speed) the maximum acceleration occurs at the point along that curve where torque is maximized. Electric motors have a much flatter torque curve with respect to rotor RPM than do combustion engines with respect to crankshaft RPM, but they still see a nontrivial drop in torque as rotor speed approaches its operating maximum. Transmissions exist to maximize the driver's access to torque: if you're traveling at 60mph on the highway with your engine spinning at 2K RPM, but your engine makes maximal torque at 4K RPM, you can shift downward to maintain your same vehicle speed while increasing the speed at which your engine turns over, thus giving you enhanced ability to bring your car up to speed before you merge with the lane to the left of you where everyone is driving much faster. A car that loses available torque at high power plant speeds and that lacks the ability to use such gearing to take advantage of optimal power plant torque will be unable to produce as much acceleration at high speeds as a car that has several gear ratios available.

Caveat: I'm just an automotive hobbyist, so if an automotive engineer rolls in and calls bullshit on anything I've said above, they're almost certainly correct.

[Diederich]

Cool, thanks!

> Caveat: I'm just an automotive hobbyist

Yeah, I'm not even a hobbyist really. (: Just interested in electric vehicles.