Tesla Cybertruck Pricing and Specs • Hacker News Board

Re: Tesla Cybertruck Pricing and Specs

#861

Post by gambiting » Fri, Dec 01, 2023, 1:16 PM UTC

drcongo wrote: post #858

gambiting wrote: post #839

Earlier quoted context omitted.

>>What's the upside? A much easier to manouver car, because you can get true variable speed ratio steering. It's explained really well here: https://www.youtube.com/watch?v=agMrewRJTow Tbh I still think it's a bit of a silly idea. But it's not completely without its merits(the one done by Tesla was though - that was completely entirely pointless).

Forgive my ignorance, but is "variable speed ratio steering" not what the Citroen SM was doing 50 years ago? https://en.wikipedia.org/wiki/DIRAVI

No, that just seems to be variable speed power assisted steering - so at high speeds it gives you little assistance, at low speeds it gives you loads.

With this it literally changes how much your wheel turns for the same amount of steering wheel/yoke movement. So at high speeds turning the yoke by 90 degrees will turn the wheels maybe 10 degrees so you don't kill yourself, but at low speeds the exact same movement will move the wheels 45 degrees so the car is a lot more manoeuvrable.

Re: Tesla Cybertruck Pricing and Specs

#862

Post by jerska » Fri, Dec 01, 2023, 1:18 PM UTC

nameistaken wrote: post #857

akmarinov wrote: post #852

Earlier quoted context omitted.

Well, not really - not much crumple zone in the front and the way the sides haven't crumpled at all means all of that force went into the occupant area. Tesla does make some of the safest vehicles, I agree, but probably not the Cybertruck. Let's wait and see the crash test results before speculating, either of us could be wrong.

[flagged]

… brings a counter theory to the parent comment to clearly explain why conclusions are hard to draw, then explicitly states that it’s inconclusive.

The bad faith and passive-aggressive tone were unwarranted.

Re: Tesla Cybertruck Pricing and Specs

#863

Post by drcongo » Fri, Dec 01, 2023, 1:27 PM UTC

gambiting wrote: post #861

drcongo wrote: post #858

Earlier quoted context omitted.

Forgive my ignorance, but is "variable speed ratio steering" not what the Citroen SM was doing 50 years ago? https://en.wikipedia.org/wiki/DIRAVI

No, that just seems to be variable speed power assisted steering - so at high speeds it gives you little assistance, at low speeds it gives you loads. With this it literally changes how much your wheel turns for the same amount of steering wheel/yoke movement. So at high speeds turning the yoke by 90 degrees will turn the wheels maybe 10 degrees so you don't kill yourself, but at low speeds the exact same movement wi…

Ahhh, got you, thanks. I'd misunderstood the Citroen system as being somewhat like your second paragraph.

Re: Tesla Cybertruck Pricing and Specs

#864

Post by simondotau » Fri, Dec 01, 2023, 1:34 PM UTC

pandaman wrote: post #666

giobox wrote: post #660

Earlier quoted context omitted.

It's not really the same at all in practice though. With steer by wire you can get the lock to lock literally as little as you like - 150 degrees at low speed lock to lock in the Lexus system for example. In theory it could go from one extreme to the other in a single degree, its just software, although obviously no one sane would implement this. Active Steering on BMWs doesn't get remotely close to 150 degree low sp…

It's a system that changes the ratio of the steering wheel rotation to the wheel angle dynamically while still mechanically linking the wheels to the steering wheel. It does not have the same parameters as Lexus system but many other things differ between BMWs and Lexuses too.

I’ve been driving a BMW with the variable ratio steering rack for over 10 years. It’s great. But it’s only variable ratio, not a dynamic ratio. Don’t confuse the two.

A variable ratio is just a regular rack and pinion setup, except the teeth on the rack are more narrowly spaced at the centre. It’s pre-defined, fixed and static. 30 degrees of steering input will always result in the same movement of the front wheels. It’s mechanically fixed.

The Cybertruck is a truly dynamic steering ratio. 30 degrees of steering input will result in a different outcome depending on othe variables such as road speed.

Re: Tesla Cybertruck Pricing and Specs

#865

Post by kllrnohj » Fri, Dec 01, 2023, 1:42 PM UTC

iainmerrick wrote: post #849

gambiting wrote: post #839

Earlier quoted context omitted.

>>What's the upside? A much easier to manouver car, because you can get true variable speed ratio steering. It's explained really well here: https://www.youtube.com/watch?v=agMrewRJTow Tbh I still think it's a bit of a silly idea. But it's not completely without its merits(the one done by Tesla was though - that was completely entirely pointless).

I just meant the yoke -- variable ratio steering would still work with a wheel, right? I'm skeptical but I can see the potential benefits of drive-by-wire, definitely. The yoke, nope (except maybe for racing drivers).

The yoke is to make visibility of the dashboard better. You can deal with rectangular screens easily then instead of needing to force things into a curve. Not necessarily a good enough reason, but it's not entirely frivolous.

Re: Tesla Cybertruck Pricing and Specs

#866

Post by qwytw » Fri, Dec 01, 2023, 1:44 PM UTC

kortilla wrote: post #803

theluketaylor wrote: post #375

Earlier quoted context omitted.

Hellcats are built to go fast in a straight line with the limitations of a 20+ year old platform. Beating a vehicle Dodge spent about $20 developing in a shed with a giant pushrod engine and hand-me-down parts they got from 90s Mercedes Benz isn't that big an accomplishment. Going fast in a straight line is easy for electric motors, so it's just not that impressive. It's like a native speaker enrolling in language 10…

> plus F-150 Raptor R does a 12.1 quarter mile. That's pretty close to running 11s That’s 10% over the ceiling. That’s not close.

It's an ICE car though, if Ford manage to achieve this despite this massive disadvantage it can't be that hard.

Re: Tesla Cybertruck Pricing and Specs

#867

Post by qwytw » Fri, Dec 01, 2023, 1:50 PM UTC

gamblor956 wrote: post #417

everfrustrated wrote: post #72

Faster quarter mile drag speed than a Porsche 911 _while also towing a 911_ That's incredible marketing. https://x.com/elonmusk/status/1730331223992472029

The Porsche 911 wasn't being driven at top speed. It has a 1/4 mile time (9.9 seconds) a full second faster than a Cybertruck (10.9 seconds). Its sort of like saying some kid on the high school track team running all out is faster than Hussain Bolt when he's running a warmup lap.

It seems they just picked a slower config to make it look better. To be fair the Turbo S which does 9.9s is 2.5x more expensive than the base config/Cybertruck.

Re: Tesla Cybertruck Pricing and Specs

#868

Post by sfjailbird » Fri, Dec 01, 2023, 1:57 PM UTC

dkjaudyeqooe wrote: post #720

jimt1234 wrote: post #704

Earlier quoted context omitted.

Engineering Explained did a really good video about this: https://www.youtube.com/watch?v=agMrewRJTow

To save going through that whole video for the answer: they have redundant power supplies (3 batteries total) and redundant actuator motors. But the fact is if there is a bad enough electrical/wiring fault, especially as the car gets older, you are toast and you have no steering. Of course the same thing can happen with mechanical steering (eg a broken linkage) it comes down to the quality of the design and build.

I've had the power steering cut out on me in a traditional ICE car, you're pretty much hosed in that situation, too, as far as steering is concerned.

Re: Tesla Cybertruck Pricing and Specs

#869

Post by kasdi » Fri, Dec 01, 2023, 2:01 PM UTC

lmm wrote: post #451

dymk wrote: post #99

Stainless steel exterior with sharp edges. Not looking forwarding to seeing pedestrians get gored when these things run into them. Not holding my breath on good crash compatibility with cars, either. If you care about humans, you won't get one of these.

I'll wait to see some credible pedestrian safety ratings rather than random eyeballing. American trucks are already designed to easily kill pedestrians; a lower shape where a pedestrian goes over rather than being knocked flat could well be less bad.

[dead]

Re: Tesla Cybertruck Pricing and Specs

#870

Post by pandaman » Fri, Dec 01, 2023, 2:08 PM UTC

simondotau wrote: post #864

pandaman wrote: post #666

Earlier quoted context omitted.

It's a system that changes the ratio of the steering wheel rotation to the wheel angle dynamically while still mechanically linking the wheels to the steering wheel. It does not have the same parameters as Lexus system but many other things differ between BMWs and Lexuses too.

I’ve been driving a BMW with the variable ratio steering rack for over 10 years. It’s great. But it’s only variable ratio, not a dynamic ratio. Don’t confuse the two. A variable ratio is just a regular rack and pinion setup, except the teeth on the rack are more narrowly spaced at the centre. It’s pre-defined, fixed and static. 30 degrees of steering input will always result in the same movement of the front wheels.…

Active Steering is dynamic. It's not in every BMW though, you can test if your car has it by turning the steering wheel when stopped: it should only require 2 turns between locks with AS.