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Tesla Roadster

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Re: Tesla Roadster

#451

Post by dzdt »

jfindley wrote: post #397
icc97 wrote: post #366

Earlier quoted context omitted.

From Wikipedia's F1 page [0]: > The 2016 F1 cars have a power-to-weight ratio of 1,400 hp/t (1.05 kW/kg). Theoretically this would allow the car to reach 100 km/h (62 mph) in less than 1 second. However the massive power cannot be converted to motion at low speeds due to traction loss and the usual figure is 2.5 seconds to reach 100 km/h (62 mph) Even adjusting for 60 mph = 2.4s, I don't see how the traction of the T…

I agree, I think this is another case of "well it works on our computer" pre-release specs that will turn out not to get close to real-world performance. The 0-100mph is very suspicious but I think the 0-60 time quoted is simply impossible for a road car, even making allowances for a few years of tech advancements. F1 tires are nothing like road tires. They're not even vaguely comparable - at normal operating tempera…

What is the best 60-to-0 time for a road car? If traction is the limiting factor, you should be able to get very close to that same time in the reverse direction.

Edit: the shortest 60-to-0 braking distance I find claimed is for a Dodge Viper ACR (Mk 5) at 87 feet. Assuming constant acceleration, that works out to 1.98 seconds.

[1] http://fastestlaps.com/lists/top-quickest-stoppers-60mph

Re: Tesla Roadster

#452

Post by chrisper »

DennisP wrote: post #446
chrisper wrote: post #432

Earlier quoted context omitted.

At a given speed, the energy is the same. But to get the car going it takes significant energy.

It takes more power to accelerate faster but the total change in kinetic energy is the same either way. Any energy consumption that doesn't go into the final kinetic energy is going into waste heat, and there can't be too much of that without melting things.

You are right... hmm

Re: Tesla Roadster

#453

Post by lovemenot »

simonbarker87 wrote: post #325
the_rosentotter wrote: post #294

There has got to be an astroturfing campaign going on here, or the HN crowd is a lot more naive than I thought. Seriously, no one is concerned that Tesla is announcing, not one, but two new products, while they are failing to deliver on all three they are currently producing (in terms of production ramp-up)? What matters more than anything to Tesla is production at scale, but they are busy promising ever more fantast…

Hitting production targets isn't enough to keep wall street happy with Tesla though, to keep raising money and servicing the debt that they have, he needs to keep creating value inflection points to stoke the hype and keep the money coming in. I agree that the main concern should be delivering cars but production delays are solvable while he is still raising money. As soon as he takes his foot off the pedal then thei…

>> Worst case scenario with his current strategy: they run out of money and an acquirer buys them for the cost of their debt and gets a company ...

Yes. And the acquiring company could be Apple, which has cash and past form in buying a company for its charismatic CEO.

Years from now, I would not be surprised to find out that a handshake deal occurred last Summer, just before Apple apparently stopped trying to make a car.

Re: Tesla Roadster

#454

Post by fma »

rottyguy wrote: post #410
tdiggity wrote: post #131

Earlier quoted context omitted.

Founder series limited to 1000 requires full deposit, that's $250 mil Base model requires $45k deposit. Not sure what semi requirements are. Even if they are biting off more than they can chew, they can gauge reaction and devote more/less to this. I'm thinking that these ventures give their engineers a space to get really creative and push the envelope. And, these advancements make their way into the mainstream model…

What's even more amazing is that F or GM couldn't possibly do this. First mover advantage plus the allure of someone like Musk is what is needed. I know many bash him for spreading himself too thin among all his other ambitions but it gives him good will capital (which can translate to economic capital) when needed.

If they need more cash then they can just have another investor round. There's enough fan boys that would invest.

I would prefer that Ford and GM not do this... I don't see how producing a $250,000 car will help the common folk, which is who Ford and GM serves.

Tesla had first mover advantage with their Model 3 and now they are floundering. GM's Chevy Bolt is out producing and out selling the Model 3 despite first movers advantage and all the 'good will' Tesla generated... Despite people saying 'GM could never do this'.

I also don't know why you would say Ford or GM couldn't do it when they produce vehicles that race in Nascar and have R&D for that sport.

Ford and GM are mature companies and expected to actually make money, while Tesla is expected to make good will and headlines.

I'll be more excited when Tesla meets their originally projected production numbers.

Re: Tesla Roadster

#455

Post by Vel0cityX »

jfindley wrote: post #397
icc97 wrote: post #366

Earlier quoted context omitted.

From Wikipedia's F1 page [0]: > The 2016 F1 cars have a power-to-weight ratio of 1,400 hp/t (1.05 kW/kg). Theoretically this would allow the car to reach 100 km/h (62 mph) in less than 1 second. However the massive power cannot be converted to motion at low speeds due to traction loss and the usual figure is 2.5 seconds to reach 100 km/h (62 mph) Even adjusting for 60 mph = 2.4s, I don't see how the traction of the T…

I agree, I think this is another case of "well it works on our computer" pre-release specs that will turn out not to get close to real-world performance. The 0-100mph is very suspicious but I think the 0-60 time quoted is simply impossible for a road car, even making allowances for a few years of tech advancements. F1 tires are nothing like road tires. They're not even vaguely comparable - at normal operating tempera…

What about weight? The Roadster is probably quite more more heavy than an F1, doesn't that play a big role in traction?

Re: Tesla Roadster

#456

Post by fma »

tlrobinson wrote: post #237
digitalzombie wrote: post #227

Earlier quoted context omitted.

> Does this mean that Tesla is pivoting from their attempt to produce a medium-priced car in quantity and going back to hand-building high-end cars? It's a halo car... Car companies build halo car to get consumers attention to their brand and to sell other models. Nissan didn't have to build the GT-R R35 but it did because it's a halo car. Another example is Toyota LFA.

I imagine some of the technology in "halo" cars trickles down to mass-produced cars too?

They might want to learn how to mass produce cars first, though...

Re: Tesla Roadster

#457

Post by fma »

samhunta wrote: post #97
Animats wrote: post #79

Earlier quoted context omitted.

Tesla doesn't run a volume production line. All the major players have production lines that make about one car a minute. Tesla isn't able to play in the big leagues until they can do that.

Fair enough, but how will they ever achieve that without first trying to compete in this outrageously competitive industry?

By solving their biggest problems first, rather than create new distractions? Kinda the same thing any company would do.

Re: Tesla Roadster

#458

Post by ajnin »

0xbear wrote: post #123
zippergz wrote: post #102

Earlier quoted context omitted.

I’m no Tesla defender, but how is anything “known” about a car that was first announced a couple of hours ago?

It’s physics, there’s no way around it. You expend a ton of energy——battery heats up. Without massive radiators there’s nowhere for that heat to go.

No, it's incorrect, physics does not mandate that battery should heat up as you expend energy. Ideally all the energy would go into kinetic energy and be dissipated by friction losses due to air or contact between the road and the tires. The battery heats up only because the process of tranferring the chemical energy from the batteries to the car motion is imperfect, and there are internal losses do to the internal resistance of the battery.

I'm not saying that Tesla has invented a sufficiently efficient battery, but to vaguely claim "physics" makes it impossible is wrong.

Re: Tesla Roadster

#459

Post by tgtweak »

usaphp wrote: post #302
davidwhodge wrote: post #187

Earlier quoted context omitted.

Hey folks. I was the one that took that video. let me know if you have any questions.

Why did you sped up the video instead of posting the original? You can see it by the movement of people around the car at the moment of acceleration.

Would be good to get an answer on this from the author since he was so kind to show up.

@davidwhodge ?

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