Lucid Air over 500 miles on a charge!

Hmp10

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Lucid is showing itself capable of creating a car with astonishing performance. Whether it or Tesla shaves additional fractions of a second off what are already outrageous track times for both has reached the point of irrelevance, except to the pubescent internet crowd. People who can actually afford either car are probably looking for a lot more in a car.

If Tesla stays with the current decade-old Model S body and can find people who will pay over $150,000 (with usual options) for a car with subpar torsional rigidity, cramped rear seats, little interior storage, and lacking such basic conveniences as rear cupholders or center armrests, then more power to them.

I'd much rather have a Lucid with a roomy, well-outfitted, high quality interior, even at the sacrifice of a fraction of second in the quarter mile or 0-60 times.

Frankly, Lucid has been foolish to get itself into a track-time battle with Tesla and lose marketing focus on the vast advantage its design offers in space and luxury while still delivering nose-bleed levels of performance.
 

ajdelange

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.... outrageous track times for both has reached the point of irrelevance, except to the pubescent internet crowd.
It's all a marketing numbers game at this point. Remember that we should think of these things more like laptops (mine's got more pixels than yours!) than as cars. Even the miles of range is getting pretty silly at this point. Not true in the truck world where half (at least) the miles are taken up by the trailer when towing.

If Tesla stays with the current decade-old Model S body and can find people who will pay over $150,000 (with usual options) for a car with subpar torsional rigidity,
No problem with torsional rigidity in the current S and X (nor I presume 3 and Y) that I am aware of (IOW if the cars are lacking in it it would take instruments to detect it - the driver can't). If there was any in the past it was long ago corrected. Why would Tesla revert to a previous design?
 

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jjwolf120

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9 anything is fast AF...shoot, under 12 is darn fast. Anyone who latches on to minor differences under the 10 second mark is ridiculous.
All of these speeds scary fast. I am a bit concerned about people crashing their cars because they aren't prepared to handle the acceleration. I heard several stories of people renting super cars and crashing them almost immediately after taking possession of them.
 

Hmp10

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Lucid posted a video of its tri-motor car hitting 9.245 seconds in the quarter mile, as shown on the electronic time board:

https://insideevs.com/news/445687/lucid-air-tri-motor-performance-drag/

There are several videos posted of the Plaid running the track at Laguna Seca, including the one Musk used at the Battery Day presentation. It shows a very specific track circuit time of 1.30.3 seconds. When it comes to the quarter mile, the only figure given is a graphic of a notably non-specific "<9.0 seconds". If they had an actual sub-9-second time, why wouldn't they give it with the same precision they give the lap time at Laguna? None of the videos I have found show a shot of an electronic time board to verify it.

Is there any corroboration that Tesla has actually gotten under 9.0 seconds yet . . . or is it just something they are planning to do by the time the car goes into production late next year?
 
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Hmp10

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No problem with torsional rigidity in the current S and X (nor I presume 3 and Y) that I am aware of (IOW if the cars are lacking in it it would take instruments to detect it - the driver can't). If there was any in the past it was long ago corrected. Why would Tesla revert to a previous design?
This 2019 source gives the Model S torsional rigidity as 19,000 n/mº with a 1st torsional moment of 42 Hz.

http://youwheel.com/home/2016/06/20/car-body-torsional-rigidity-a-comprehensive-list/

It is among the lowest of any sedan on the list, edging toward the territory of some convertibles.

Despite the desirability of a hatchback for loading cargo, Peter Rawlinson insisted that the Lucid Air use a trunk specifically because he felt the hatchback had compromised the Model S body's stiffness too much.

I know cowl shake or other signs of torsional weakness when I feel it, as I've owned pre-C5 Corvettes. I experience no cowl shake or other signs of torsional weakness in my Model S . . . nor did I in my Audi R8 V10 Spyder before that. However, I believe one of the reasons the Model S has a less compliant ride than most German sedans is because of the additional suspension stiffness to offset the "springiness" of the body.
 

ajdelange

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I know cowl shake or other signs of torsional weakness when I feel it, as I've owned pre-C5 Corvettes. I experience no cowl shake or other signs of torsional weakness in my Model S . . . nor did I in my Audi R8 V10 Spyder before that.
Then why do you care that the S is half as stiff as a some Porsche models but nearly twice as stiff as others? How does it compare to the Lucid's?

You are trying very hard to convince yourself that your PC is better than my Mac. That's fine. I'm sure we all want you to be happy with your choice and I'm sure you will be. Just don't try to sell the rest of us - especially not in a Rivian forum. Of course we are all interested in anything new from any manufacturer but I think we'd also appreciate your toning down the Tesal FUD a bit.
 

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. . . especially not in a Rivian forum.
I did not start this thread. Someone else did. But, at nine pages and still going, it seems there is plenty of interest in Lucid on this Rivian forum.

As for caring about the Model S stiffness, I think the effect shows up in a less-compliant suspension. The roughness of the ride was the reason I opted for the 19" wheels when I ordered my Tesla in 2015. I'm hoping Lucid has the body stiffness to use a more compliant suspension. Since Rawlinson resisted pressure to go with a more popular hatchback design over the issue of stiffness, I assume it has some relevance to the car's engineering. Since the Lucid prototypes were first revealed three years ago, the odd look of the clamshell trunk has drawn the most negative commentary of any feature, yet he has stuck with it. I have no reason to doubt the reason he's given.

I own a Tesla and like it just fine. I'd be buying another one over a new entry to the market if Tesla had a model that met my current needs, simply because I'd prefer to avoid the risks of buying a less time-tested car such as Lucid will be.

I've considered buying a Model X and test driven them a few times. But I simply refuse to pay $120,000 for a vehicle that has no door storage pockets and requires you to buy a strap-on aftermarket armrest if you want somewhere to rest your arms in the rear seat. Perhaps unlike you, people in my household need a place to store a handicap placard, an array of reading glasses and sunglasses, a roll of paper towels, and such things. In south Florida, we also find ventilated and cooled seats useful . . . you know, the kinds of features most cars at less than half the price offer these days.

I'm keeping my R1S reservation, by the way. I may well get delivery on it before the Lucid Air.

As for what other people do and don't appreciate about my posts, I'll wait to hear from them.
 
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ajdelange

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I think you are confusing beam stiffness and torsional stiffness and I think you have been reading stuff that was published before BEVs came onto the scene. In the old days of the longitudinally mounted ICE the drive shaft ran the length of the car. The engine produced torque, this was multiplied by the gearing in the transmission and sent down the drive shaft. The chassis had to provide opposing torque about the longitudinal axis and if it were not stiff it would twist. In BEVs the motors are transverse and while the chassis must still provide opposing torque it is now about the wheel axles. The torsional stiffness of the frame is no longer so important. I'd look for something else to worry about.Nonetheless a little poking about reveals that formula 1 cars had resistances of around 30,000 Nm/°. These cars have half that. I'd focus my attention on the cup holders.
 

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The other new-tech aspect of this is the "adaptive suspension". In the old tech when you hit a bump with a wheel the "shock" (or much of it) was absorbed by a spring and then slowly dissipated in a dashpot. Now when you encounter a bump the car daintily just picks up the tire so there is no shock. Of course this doesn't work perfectly any more than the old shock absorbers did but unlike them the systems are adaptive to both road conditions and driver preference, Obviously driving over a rock with the left front wheel will put a sudden clockwise torque on the frame which, if it is not stiff, will twist. Cancelling out most of this shock means no torque and no twist thus torsional stiffness becomes less important from this POV too. But the cars' designs retain enough stiffness to operate safely under the old way of doing things nonethelss.
 

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The other new-tech aspect of this is the "adaptive suspension". In the old tech when you hit a bump with a wheel the "shock" (or much of it) was absorbed by a spring and then slowly dissipated in a dashpot. Now when you encounter a bump the car daintily just picks up the tire so there is no shock.
I believe you are confusing "adaptive suspension" with "active suspension".

An active suspension, such as those available on some Mercedes and other high-end models, uses actuators to raise or lower the wheel based on conditions such as road surface and body lean. These systems can make a car "lean into" a curve as well as step over road irregularities to a certain extent. These systems involve cameras or other sensors to read the road surface, computers to process the inputs, and servos to effect the wheel height changes. They are expensive to build and maintain and not in widespread use.

Adaptive suspensions are those that do not actively move the wheel but rather adjust suspension damping characteristics on the fly by techniques such as adjusting the charge of a magnetic field in the damper fluid or changing the air or oil valving in the damper. These systems are much more common and used by mass manufacturers such as GM and VW. My three Audi R8's all used the magnetorheological fluid adjustment approach.

Lucid is using what it calls "semi-active dampers". They have not explained the term, and I suspect it's some version of an adaptive system. As near as I can tell, no EV to date has had a true active suspension. I suspect this is because the energy required to raise and lower the wheels constantly is considerable enough to noticeably impact range.

My Tesla has the air suspension option. I assume it uses adaptive damping technology, but I can assure you it is not an active suspension that "daintily picks up the tire so there is no shock".
 

Hmp10

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I think you are confusing beam stiffness and torsional stiffness and I think you have been reading stuff that was published before BEVs came onto the scene.
Peter Rawlinson led the chassis and suspension engineering of the Model S. (In fact, Musk is now claiming that's about all he did, despite plenty of evidence to the contrary.) I'm pretty sure he understood the difference between beam and torsional stiffness, and I'm pretty sure he knew the Model S would not have a longitudinal driveshaft. Yet he found the penalty the hatchback opening exacted on frame stiffness to be problematic enough to take steps to avoid it in the Air.
 

ajdelange

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First off, I don't think you are qualified to lecture engineers on the meaning of engineering terminology.

Second, the Teslas have adaptive suspensions. They sense the road, predict the necessary correction to wheel position and activate some sort of servo to "daintily" raise or lower the individual wheels to smooth the ride and keep the vehicle level.


IMG_1407.jpg


Note the graphical display of the control currents to the actuators trailing each wheel. Don't ask me to explain what the actuators are, what they do or what the adaptive control algorithms behind them are because I don't know but I'd bet more than one beer that fuzzy logic is involved. Note that the 4 wheels are at different heights as is necessary to keep the car level on my uneven gravel driveway. Note also that each wheel is equipped with its own accellerometer.
 
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AJ, you've clearly stepped out of your wheelhouse here. Torsional stiffness is still very much critical to optimal suspension operation. The chassis is essentially a 5th spring in the suspension... and an undamped one at that. Of course, as with all things engineering, there are always tradeoffs involved. Discussion of how much torsional rigidity is enough generally starts by looking at the roll stiffness of the vehicle... not the powertrain.

Hmp10, I haven't driven a Model S so I can't speak to its ride quality. However, in this case, I suspect the rough ride you report is attributable to factors other than the result of (or compensation for) the torsional rigidity. While it could have been better, it is far from poor. Beyond a certain point, issues of torsional rigidity manifest more in handling characteristics than comfort (edit: also manifests as various squeaks, rattles and vibrations within the cabin). I suspect the suspension is simply tuned to be "sporty". Combine that with the fact that the S is quite heavy and low to the ground and it likely has a relatively limited amount of available wheel travel to absorb impacts resulting in the roughness you describe.
 
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