Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Tesla Roadster

tesla.com

Post reply on HN
Print view View original

691–700 of 729 posts

Re: Tesla Roadster

#691

Post by ska »

killjoywashere wrote: post #682
ska wrote: post #610

Earlier quoted context omitted.

Accelerating at > 1g off the line has its own set of issues - without extra downforce from somewhere you have traction problems regardless of tires, street tires just make it worse. This is why you see so many approx 2.9s 0-60 times in higher end sports cars, it's hard for aerodynamics to affect it much over the first couple of seconds.

Correct me if I'm wrong, but isn't downforce an aerodynamic issue? There are no aerodynamics at 0 mph. You do have a torque problem, but the Tesla is actually a fairly heavy car, is it not? Also, isn't Tesla's center of mass pretty near the same height as the axles? So it's not like the rear end is going to get under the front end.

Sorry, i just worded it badly. The point is that without downforce, you can't overcome the traction issue. To a first approximation at 1g accel from a standing start, your resulting force vector is at 45 degrees (mass at 1g down, accel at 1g forward). Accelerating harder just makes the problem worse. At speed, the answer to this is downforce (e.g. how F1 cars can corner as fast as they can).

But for the first couple of seconds, you can't generate much downforce from aerodynamics because you aren't going fast enough. And there are limits to what a spoiler, etc. can generate. For a lot of street legal sports cars, this all evens out about the same way, and they end up with very similar 0-60 times.

If you try and systematically knock down all of these problems, you'll end up with a top fuel car. In that case you may get ~1000lb of downforce from exhaust alone, which gets you past the first bit while you are going too slow for the big wing to be really effective.

Re: Tesla Roadster

#692

Post by greglindahl »

Sohcahtoa82 wrote: post #653
Robotbeat wrote: post #542

Earlier quoted context omitted.

The car also has record-setting 0-100mph times. And I'd argue for most uses, 0-45mph is more important, and all electric cars pretty much do awesome there.

> and all electric cars pretty much do awesome there The Chevy Bolt with its 6.5 sec 0-60 begs to differ.

A friend of mine who owns a Leaf and a BMW 3-series was impressed that the Leaf was amazingly quick from a dead start... up to low speeds. The Bolt is faster than a Leaf, so there's your awesome, at least from my BMW-loving friend.

Re: Tesla Roadster

#693

Post by scott_karana »

DenverR wrote: post #117

They clearly learned the power of the preorder with the Model 3! This is a great way to raise funding without going back to the equity markets. Say they can fill up all the founder series slots along with 5,000 regular slots, that’s $500,000,000. Smart :)

The S and the original Roadster had highly publicized pre-orders too... nothing new for them. ;)

Re: Tesla Roadster

#694

Post by Tiktaalik »

dkhenry wrote: post #448
wintermute2001 wrote: post #125

Am I the only one who's worried that Tesla is really starting to bite off more than they can chew? Right now their finances are a mess, they are publicly struggling to produce their most important car ever, their CEO is spending time figuring out how to dig holes underneath LA...and now they're announcing a semi truck and a roaster in the same day? Don't get me wrong, Teslas are incredible cars. But this seems like a…

You have been reading too many finance blogs. Their finances are far from a mess, they are just not what finance people like to see. They have cash on hand and a roadmap to execute on. If they don't execute they will go out of business, and they will take my money as an investor with them. I'm OK with that and as long as they continue to have a path to profitability I am all on board. I want to see them burning money…

> If they don't execute they will go out of business

Well this is exactly the concern. Tesla seems to be struggling to execute on their plan to build Model 3s.

Re: Tesla Roadster

#695

Post by scott_karana »

kwhitefoot wrote: post #645

But you have to get out of the car and remove the roof to use it as a convertible. Then I think I'd stick with a BMW 438i convertible which takes the entire roof down at the push of a button in about 20 seconds. Driving isn't all about acceleration.

Modern Corvettes, and classic Porsche 911 Targas all have similar roofs. They are less practical, but lighter, and sell well.

Re: Tesla Roadster

#696

Post by taurath »

illumin8 wrote: post #643
dkhenry wrote: post #448

Earlier quoted context omitted.

You have been reading too many finance blogs. Their finances are far from a mess, they are just not what finance people like to see. They have cash on hand and a roadmap to execute on. If they don't execute they will go out of business, and they will take my money as an investor with them. I'm OK with that and as long as they continue to have a path to profitability I am all on board. I want to see them burning money…

If Amazon listened to those same finance blogs that are chastising Tesla, they wouldn't be where they are today. Wall Street hates companies that invest every cent they make into future growth; they want solid companies like GE and IBM that pay out regular profits to investors, and end up old dinosaurs because they didn't invest in innovation. The market analysts and financial blogs may hate companies like AMZN and T…

If they retooled to maximize profitability now they would not be worth the multiple they are.

Re: Tesla Roadster

#697

Post by funnelsgun »

stochastic_monk wrote: post #642
bpicolo wrote: post #570

Earlier quoted context omitted.

Ford and GM can absolutely do this. Tesla is "hot", but Ford is successful. People underestimating the big players and cars aren't thinking about the economics right. Ford markets are almost two orders of magnitude more than Tesla is producing. If Ford sees the global opportunity to sell 10-20 million EVs a year they'll build the crap out of them.

Ford sells pieces of shit and then tells you you're crazy every time you report a problem -- until a month after your last complaint when there's a company-wide recall. I am never doing anything that gives them my money again. Source: [ashamed] owner of Ford for 3+ years.

Focus RS head gasket failure per chance?

Re: Tesla Roadster

#698

Post by bllguo »

grkvlt wrote: post #632
bllguo wrote: post #619

Earlier quoted context omitted.

Oh please. I should hope that people aren't so intoxicated on the Kool-Aid that when Tesla claims the Roadster outperforms the fastest production cars in the world, people want to dig deeper. You're seriously implying that blindly accepting what they say is better?

No, no - it's just the 'only exists in CGI' I have an issue with, since people are arguing against factual evidence. But, this is a prototype, so of course I expect the performance figures are going to change, and speculation about that aspect is par for the course and I have no problem with that.

Ah, fair enough. Apologies for an unintentionally hostile tone.

Re: Tesla Roadster

#699

Post by stochastic_monk »

funnelsgun wrote: post #697
stochastic_monk wrote: post #642

Earlier quoted context omitted.

Ford sells pieces of shit and then tells you you're crazy every time you report a problem -- until a month after your last complaint when there's a company-wide recall. I am never doing anything that gives them my money again. Source: [ashamed] owner of Ford for 3+ years.

Focus RS head gasket failure per chance?

Transmission.

I think this is the one. http://fordpowershiftlawsuit.com/

Re: Tesla Roadster

#700

Post by Sohcahtoa82 »

dmode wrote: post #659
Sohcahtoa82 wrote: post #590

Earlier quoted context omitted.

God damn....that acceleration is almost cartoon-like. I'm kinda sad about the $200k price tag. I was planning on budgeting $125k for my next car in 2022. Obviously options have yet to be announced, but I'd really like to see a 100 kwh option for a cheaper price. That would give about a 300 mile range which would be plenty for me. Considering they announced 200 kwh as the base though, I'm not exactly holding my breath…

You can probably get a P150D or whatever it will be at that time. Which will give you Roadster like acceleration, probably 400-500 mile range, and will still be a family sedan.

I don't want a family sedan, I want a small, reasonably agile coupe. My current car is a Subaru BRZ. I want something that still has that kind of handling.
Post reply on HN