LR RWD/AWD "uncorking" in our futures?

[ratsbew]

It's pretty common knowledge by now that there is only one rear motor that is shared among the RWD, AWD, and Performance Model 3.

What are the odds that "old" RWD and AWD cars eventually get an "uncorking" to improve the off the line acceleration?

AWD to 3.9 seconds 0-60
RWD to 4.3 seconds 0-60

It's possible that Tesla has this on their product roadmaps to help keep their cars fresh even after they've been on the roads for several years.

 

[doehringm93]

As RWD owner, I'd be pretty happy about this. If it does happen, I don't think it'll be for quite a while.

 

[AlanSubie4Life]

As RWD owner, I'd be pretty happy about this. If it does happen, I don't think it'll be for quite a while.

The P would have to be “uncorked” first; I don’t think they’re going to do this if they don’t give more to P customers as well. Can you imagine the uproar, based on recent events?

Then that brings up the question of how much more (if any) margin/capability the (identical design, better screened) P motors have, due to their better selection criteria (distribution selection and extra burn-in). We don’t know how much more torque those (identical design) P motors will be able to produce before running into problems.

I would think Tesla will want to figure out all the reasons drive units are failing first, to make sure they’re not going to increase failure rates significantly by boosting the torque. Then maybe they consider adjustments to RWD/AWD/P torque.

In any case, if there is anything left on the table (for the P) it seems like it’s going to be an addition of torque, but not an increase in max power (while torque would start higher, torque would have to taper earlier (at lower RPM), once max power was reached), since presumably they can’t push the battery much more? For the RWD/AWD perhaps they could make max power higher than it is currently, since the max power draw from the battery is lower than the P. Actually maybe the peak power draw is the same for AWD & P (????)... Someone should post instrumented acceleration data side-by-side for AWD & P to clarify the actual differences for this discussion...this last paragraph might not be correct based on known performance data. Anyway, I guess if there is more margin in the battery max power draw, they could increase peak power as well, but I doubt they will change it much.

 

[Knightshade]

The P would have to be “uncorked” first; I don’t think they’re going to do this if they don’t give more to P customers as well. Can you imagine the uproar, based on recent events?

Not really.

They already did exactly that on the S and X.

The S75 got ~1 full second quicker, the P100D didn't change at all. So knocking a couple tenths off the non-P 3 wouldn't be much of an issue.

Especially when Tesla is reporting the non-rollout times for them today, but the rollout one for the P.

So knocking .2 off each would just bring them back to the "listed" difference they had before Tesla started using the rollout # on the P.

Then that brings up the question of how much more (if any) margin/capability the (identical design, better screened) P motors have, due to their better selection criteria (distribution selection and extra burn-in). We don’t know how much more torque those (identical design) P motors will be able to produce before running into problems.

Given there's only 1 part number it means all Ps will get the same replacement motor in case of a failed unit that LR AWD or LR RWD owners will.

So there's no actual reason to suspect Ps can "handle" any more power than the other LR models.

Someone should post instrumented acceleration data side-by-side for AWD & P to clarify the actual differences for this discussion...this last paragraph might not be correct based on known performance data. .

We've already seen this in other threads. Most of the difference is at low speed- by the end of the 1/4 mile there's relatively little difference between AWD and P (but still a lot between RWD and the other two- obviously from lack of a second motor)

 

[AlanSubie4Life]

I (and I think the OP) am talking about actual changes. Not definition changes.

You may be right on the motors. But the current motors may or may not be capable of more torque, reliably. We’ll see.

All I was saying is I think in this case Tesla won’t change AWD/RWD without also changing P. I could be wrong.

I haven’t seen side-by-side instrumented (acceleration vs velocity might be nice as a view of torque vs. rpm) plots for AWD and P. If you would like to point me to them, please do so. I agree with your basic summary and it is consistent with my thinking, but that is so much less useful than a plot.

Next week I may have side-by-side instrumented data myself. But would love to spare myself the trouble!

 

[AlanSubie4Life]

Given there's only 1 part number it means all Ps will get the same replacement motor in case of a failed unit that LR AWD or LR RWD owners will.

Another way to look at this is that all LR AWD/LR RWD will receive the same great replacement motor as the Ps do!

 

[StellarRat]

I think those older models were more experimental, so they were conservative on power at first then later on figured out that pushing the batteries and motors wouldn't hurt them, so they "uncorked" them. I'd be more surprised if the performance could be improved as much as you suggest on the Model 3. They've probably learned enough that new car is closer to what's possible already.

 

[Knightshade]

Several folks have posted draggy results in 10 mph increments for both AWD and P but you'd have to search to find them...

The other major data point I think were the 1/4 mile videos of a P vs RWD and a P vs AWD where trap speeds on the P and AWD were only like 2 mph apart, while the RWD and AWD were nearer 10 mph apart.

I also have some notes handy on passing times from a previous discussion if it's any help, these too show the RWD/AWD gap tends to be a lot larger at speed than the AWD/P gap, supporting the idea mostly they're just software nerfing the AWD particularly from 0/at low speeds.

30-50:
LR 1.9, LRD (AWD): 1.5, P: 1.2

50-70:
LR 2.8, LRD (AWD): 2.1, P: 1.7

Another way to look at this is that all LR AWD/LR RWD will receive the same great replacement motor as the Ps do!

Which makes sense since that's what they started with anyway
(probably for RWD, and for certain for AWD)

 

[Knightshade]

I think those older models were more experimental, so they were conservative on power at first then later on figured out that pushing the batteries and motors wouldn't hurt them, so they "uncorked" them.

Uh- those aren't older models. The S75 is the current entry level Model S.

They'd been making/selling cars for years at that point.

They uncorked the S75 because they didn't want to be selling an S that was slower than a 3. (the announcement came right at the same time as 3 production began)

I
I'd be more surprised if the performance could be improved as much as you suggest on the Model 3. They've probably learned enough that new car is closer to what's possible already.

Well, we know for a fact they can improve the AWD by 1 full second, since it's physically the same car as the P3D- is.

In fact several owners who ordered a P3D- got an AWD at delivery and they software flashed it into a P.

The RWD I doubt they could improve to that degree since it lacks the second motor, but I'd be surprised if they can't get at least a couple tenths out of it.

 

[StellarRat]

Well, we'll see. I thought the P had some different hardware in it to take the extra power loads. If all it is is software than that's a different story. All I know is that there is rarely such a thing as a free lunch.

 

[JGard]

Funny timing, this thread. I had a mobile tech over today to address a possibly blown strut issue, and we were just talking about the car in general. I have a RWD. He said Tesla plans on selling a performance upgrade for these RWD models, too. Just a software unlock. And continued by saying he's spoken to engineers about these cars and they claim these cars are nerfed big time and still have a ton more performance available.

So I don't know, maybe he was talking out his ass, but it sure got me excited. Even if I had to pay like $3k more, if the car could be like half a second or more faster 0-60, I'd buy it in a second.

 

[ratsbew]

they claim these cars are nerfed big time and still have a ton more performance available.

Was that the RWD specifically, all Model 3s or the Performance?

 

[AlanSubie4Life]

I'll amend my opinion above to:
I don't think they'll do this for FREE without also providing more power to the P version first/at the same time. However, it seems like they could make money upgrading the AWD/RWD for a fee - and they might do that, especially if there is no additional safe power available from the P. It's an alternative option that wouldn't make P customers too upset. They've already stirred up that hornet's nest!

No matter what, I think they're going to wait until reliability/failure modes are well understood, and they won't do anything if it's going to substantially increase drive unit failure rates. (I don't know how long that might be.) For a fee, they could tolerate some additional failures that result, but then they'll have to have their actuaries look at it and adjust their warranty reserve liability accordingly.

 

[StellarRat]

I'll amend my opinion above to: No matter what, I think they're going to wait until reliability/failure modes are well understood, and they won't do anything if it's going to substantially increase drive unit failure rates. (I don't know how long that might be.) For a fee, they could tolerate some additional failures that result, but then they'll have to have their actuaries look at it and adjust their warranty reserve liability accordingly.

Thank you. That was the "free lunch" I was referring to...will they break more often if more power is available? There is a cost for everything.

 

[JGard]

Was that the RWD specifically, all Model 3s or the Performance?

He and I were specifically talking about my car (RWD), but you have to figure all of them are being nerfed, still, all for the sake of better range. The tech and I both felt that it was more important for Tesla to get that >300 mile range than have the best possible performance from these cars.

 

[AlanSubie4Life]

He and I were specifically talking about my car (RWD), but you have to figure all of them are being nerfed, still, all for the sake of better range. The tech and I both felt that it was more important for Tesla to get that >300 mile range than have the best possible performance from these cars.

As I understand it, adding more torque and power should have nearly zero impact on range, assuming the car is driven conservatively within the current performance limits. It's a benefit of modern computer-controlled electric propulsion systems. For an ICE you'd be tweaking fuel-air, exhaust, intake, resonances, etc., and cruising efficiency might be affected (positively or negatively) by performance adjustments.

 

[JGard]

As I understand it, adding more torque and power should have nearly zero impact on range, assuming the car is driven conservatively within the current performance limits. It's a benefit of modern computer-controlled electric propulsion systems. For an ICE you'd be tweaking fuel-air, exhaust, intake, resonances, etc., and cruising efficiency might be affected (positively or negatively) by performance adjustments.

Well if you get on the accelerator more, you're going to have less range. But yes, if you drive similarly, it shouldn't affect anything that way. I wonder if it's a tires thing. They need these crummy low-resistance tires to get the range to where they want. Elon has even said if you put wider tires on, performance will be better, but range will suffer. 235s are already too narrow for the speculative amount of power and weight of this car, so I feel like that is why it's nerfed. Not exactly just drivetrain related, but to the tires as well. If you add a lot more power to these tires, they'll never hold.

 

[Az_Rael]

Funny timing, this thread. I had a mobile tech over today to address a possibly blown strut issue, and we were just talking about the car in general. I have a RWD. He said Tesla plans on selling a performance upgrade for these RWD models, too. Just a software unlock. And continued by saying he's spoken to engineers about these cars and they claim these cars are nerfed big time and still have a ton more performance available.

So I don't know, maybe he was talking out his ass, but it sure got me excited. Even if I had to pay like $3k more, if the car could be like half a second or more faster 0-60, I'd buy it in a second.

If true, this is terrible news for my pocketbook.

 

[MIT_S60]

Not really.

They already did exactly that on the S and X.

The S75 got ~1 full second quicker, the P100D didn't change at all. So knocking a couple tenths off the non-P 3 wouldn't be much of an issue.

Especially when Tesla is reporting the non-rollout times for them today, but the rollout one for the P.

So knocking .2 off each would just bring them back to the "listed" difference they had before Tesla started using the rollout # on the P.






Given there's only 1 part number it means all Ps will get the same replacement motor in case of a failed unit that LR AWD or LR RWD owners will.

So there's no actual reason to suspect Ps can "handle" any more power than the other LR models.




We've already seen this in other threads. Most of the difference is at low speed- by the end of the 1/4 mile there's relatively little difference between AWD and P (but still a lot between RWD and the other two- obviously from lack of a second motor)

Uh- those aren't older models. The S75 is the current entry level Model S.

They'd been making/selling cars for years at that point.

They uncorked the S75 because they didn't want to be selling an S that was slower than a 3. (the announcement came right at the same time as 3 production began)




Well, we know for a fact they can improve the AWD by 1 full second, since it's physically the same car as the P3D- is.

In fact several owners who ordered a P3D- got an AWD at delivery and they software flashed it into a P.

The RWD I doubt they could improve to that degree since it lacks the second motor, but I'd be surprised if they can't get at least a couple tenths out of it.

For the Model S 75, they uncorked all (or mostly all) S75D models, including those built before the July 2017 announcement and those after (from 5.2 seconds down to 4.2 seconds 0-60). For the S75 RWD, they only uncorked those built after July 2017 (from 5.5 seconds down to 4.3 seconds 0-60). Any S75 RWD built from April 2016-June 2016 are still locked to the slower times (5.5 seconds 0-60). I've been following that very closely, and have been disappointed that the RWD models didn't get the uncorking option (I'm sure many of us would gladly pay for the uncorking if it were ever offered, but at this point that doesn't seem like it will ever happen since they discontinued the S75 RWD).

 

[AlanSubie4Life]

I wonder if it's a tires thing. They need these crummy low-resistance tires to get the range to where they want. Elon has even said if you put wider tires on, performance will be better, but range will suffer. 235s are already too narrow for the speculative amount of power and weight of this car, so I feel like that is why it's nerfed. Not exactly just drivetrain related, but to the tires as well. If you add a lot more power to these tires, they'll never hold.

The MXM4s, as discussed elsewhere, are very efficient, and not terrible for grip, but nowhere near as good as the PS4S for grip (but much better for efficiency). So yes efficiency is all about the tires.

In a straight line, however, neither the MXM4 or the PS4S, for the AWD and RWD, are near the traction limit. You can see this because even the Performance without PUO does not generate sufficient torque to break the tires free. For cornering, they're undersized and not sticky enough and better tires will make it much better. But, you actually have to add a fair amount more power even to the P3D before it will become traction limited in a straight line (you can see the approximate traction limit of the stock MXM4 tire by looking at the 60-0mph g-force: POLL: What will my 60-0 stopping distance be with Pilot Sport 4S 265/40R18s be? ).