I can't see any logic behind different drive trains in P+ vs P- cars. Bigger wheels and brakes does not necessarily equate to more/less stress on a drive train, plus different part variations adds that much more complexity to the manufacturing process. You'd think Tesla would keep it simple, and vary as few parts as possible.
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I ordered a Performance 3. The car at delivery was an AWD.
- Thread starter yul sam
- Start date
Knightshade
Well-Known Member
Many folks, myself included, think that's exactly what Tesla actually did, and at best if they're testing/binned at all then out of every batch that they test, the highest X number (based on % of actual P orders) go in known-P cars as it might marginally reduce warranty costs without really adding significant complexity to supply chain, manufacturing, or repairs like "real" different parts would.
But I'd about bet real money literally any AWD car can be flashed to a P and work just fine.
I'd like to see a test with n cars at the same SOC and temperature driven at the same high speed to measure variation in thermal limiting...
maybe they did try the binning and realized that all the motors are just as badass and can be pushed just as hard without catastrophe so it was pointless? (and maybe that was already posed...didn't quite read all posts)
Pretty sure the model S P motors can put out something like 20% more
Pretty sure the model S P motors can put out something like 20% more
Glamisduner
Active Member
Who know's maybe in the future tesla will offer a software flash for only $11k to upgrade your AWD's to P models.
Free temporary upgrade to escape an alien invasion.
Jedi2155
Model 3 has Arrived.
That does not sound plausible to me because that would imply they did not know the value of binning before hand.
Possible but likely? No.
Or that they knew binned motors were incrementally better than non-binned and either abandoned the process or decided it would make no difference which motor went into what car.
If they even binned the parts, which I am in the camp they didn't, my theory is it's only for the P+ models. The reason is track mode, and the extra stress that will exert on the car. Also, future ludicrous upgrades.
Knightshade
Well-Known Member
It's entirely possible they expected larger variance between production motors than they ended up with- either through improved manufacturing or simply better parts tolerances
Intel chips, which people keep liking to reference here for binning, have had vastly different amounts of yeild quality from one process to another over the years- sometimes producing an abundance of high performing parts they had to "force" to be downgraded parts just to have a cheaper part to segment the market, and some producing poor yields that made higher end chips more rare.... and CPUs are a lot more delicate to build than EV drive units.
The whole idea of binned motors sound absolutely unreal. The motors relatively are simple constructions and do not have measurable variations, or they are too small to take it into account. CPUs quality is very dependent of quality of semiconductor and can very a bit.
Also, to distinguish one CPU from another is easy enough measuring power consumption. To compare and find difference between two similar motors will take more time/money and is not worth it. I do not remember where, but somewhere in this forum I saw link or chart with motors descriptions for RWD, AWD, and Performance AWD.
Also, to distinguish one CPU from another is easy enough measuring power consumption. To compare and find difference between two similar motors will take more time/money and is not worth it. I do not remember where, but somewhere in this forum I saw link or chart with motors descriptions for RWD, AWD, and Performance AWD.
Drive units have inverters, inverters have SiC FETs, SiC FETs have 40% variation per data sheet.
CPU testing involves clock rate vs voltage, not power dissipation. The motor testing they do anyway can measure electrical to mechanical efficiency. It's added data, not added test cost (unless they test twice as long).
It is interesting how as Tesla owners, we have to speculate so many aspects of our car instead of Tesla officially letting us know. What major car company makes us guess at the specification of the car that you actually paid for. There is a lot of speculation on new future models but never on one that is physically delivered. Why do we have to speculate and fuel bad information rather than propagating facts based on OEM specification sheet? Is this what we have to accept as a default when dealing with behavior from companies that is on the bleeding edge of innovation. Maybe we are not demanding enough from Tesla to be accountable just because they are innovating. I am venting a little because as a new Tesla owner who is reading the forum to get useful information and help is finding a lot of misleading and factually wrong information being propagated because of the speculative nature of the information being provided rather than facts being stated.
The fact that inverters have semiconductors does not mean they work differently. Otherwise we should talk about binned inverters, not the motors. It is like to say that one TV have more frames per sec than another one. All this schematics frequency controlled by quartz and have the same characteristics. These inverters are not not build to work on the "edge" their characteristics, it will be too expensive to burn them, or try to test them "on the edge".
Talking about CPU testing: yes, clock rate testing is actually involves power dissipation and generally the one that has lower power dissipation on some frequency will have lower dissipation on a higher frequency. Power dissipation is specified, so you are limited what clock you will use CPUs with.
Elon stated the sort was for drive units: combined rotor, gears, and inverter.
A typical ST SiC 650V FET has a 25 C on resistance range of 18 to 26 mOhm. That is a 44% variation in internal dissipation for the same current level. Avoiding the edge requires designing to the worst case number vs nominal and thus derating the peak current/ peak torque/ peak power. By sorting/ testing/ binning, they can find the parts that are closer to nominal and get up to 20% more power from the inverter. Or, for the same power level, units that will produce 40% less heat (more laps around the track). They can also find parts better than nominal, for even more performance.
I notice he says lot sorted, so it may be that STMicro is binning the SiC FETs at their factory (similar to LED suppliers) so the inverters have a known power level, then they double burn-in only those drive units.
Swampgator
Active Member
Mongo,
This still does not square with the RWD/P rear motor reported outputs. There is, IMO, no way that Tesla has been binning the higher performance motors from day 1 for RWD, and holding back the lower performing motors for AWD (now at 6k premium over rwd)
No way Jose.
Why do you think RWD cars need to have higher performance motors?
Are you speaking of the 211kW number from the EPA filing?
Tesla publishes an average/ continuous power number. That is not the peak power or torque from the unit.
RWD has a weight of 3,838 lbs and has a 0-60 of 4.6 seconds.
In metric land that is 1745 kg, and 26.8 m/s. Total energy (1/2*m*v^2) of 627.5 kJ or 0.1743 kWh (ignoring friction and areo). Assuming a linear speed increase, the peak motor energy is 273 kW (a minimum of 29% over published).
Beyond peak power, for track use, long term thermal is the limiting factor. A motor that can do 300 Hp for 5 laps is better than one than can only do 3 laps.
Daniel in SD
(supervised)
Acceleration of the LR is only linear (constant torque) up to about 45mph then it hits it's peak HP. Also the 4.6s number is erroneous and includes 1 foot rollout. It's really about 5.1s. Anyway it dynos at 325hp (242kw) so yeah the EPA number is low.
Why do you think the P rear drive unit makes more power when the P is only 33% faster to 60mph? The simplest thing for Tesla to do would be to put a front unit with 150kw or so of power and call it a day.
The x axis on this dyno plot might not be quite right. They did it on a hub dyno.
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