Swampgator
Active Member
Are you then of the opinion that Tesla is dropping less powerful motors in the rear of the AWD cars? For a 6K premium?
I ordered a Performance 3. The car at delivery was an AWD.
- Thread starter yul sam
- Start date
I don't have a position on the short term power output. I think a binned motor could support more, but the average unit puts out plenty of power. I think the continuous dissipation and operating temperature is more of a factor for the track usage case.
That post was only to show that having 211kW for RWD and P doesn't really indicate anything (just like the range number staying the same with different MPGe).
Daniel in SD
Well-Known Member
No. All indications are that the power output of the AWD and P are almost identical. 1/4 mile trap speed is very close. The AWD has less torque but that is likely entirely a software limitation.
Mongo is arguing that the P motors are slightly more efficient than the AWD motors. When the drivetrain is extremely efficient a small change in efficiency can produce are a large change in waste heat. For example if you go from 95% efficiency to 96% you've dropped the cooling requirements by 20%. However I bet that most of the loss is in the motor and battery and can't be easily improved.
More so that the greatest variability in heat generation is at the part most sensitive to it: the power devices in the inverter.
Daniel in SD
Well-Known Member
But unless the system is poorly designed I would think that the it is limited by the size of the radiator and air flow over it.
I guess none of us really knows what the limitation is. Given that we know that P3D heat soaks over a period of 5 minutes or so (a few laps) it seems like it must be the radiator and coolant. Those power transistors have very little thermal mass themselves.
Both are factors. Maximum thermal dissipation is proportional to the max junction temperature of the die, temperature of the mounting block and the thermal resistance. Die thermal mass is insignificant, but the mounting block gives a short time constant buffer and will tend toward the coolant temperature. The colder the coolant, the colder the block, and the more power the FETs can handle. Within that thermal budget, the heat generated by the FET is current squared times resistance (along with switching losses).
So a 40% better FET resistance gives the same advantage as coolant that is 40% cooler relative to the FET. If you run the max junction at 175C and your coolant is 100C for a great part, it would need to be 70C for the poor part (steady state).
Note these temperature numbers are made up.
Daniel in SD
Well-Known Member
I bet the battery is the limiting factor for maximum coolant temperature. I think everything is on the same loop.
It's possible that it could still be the motor limiting things like it does in the Model S but my understanding is that pumping heat out of the permanent magnet motors is not a problem.
It's possible that it could still be the motor limiting things like it does in the Model S but my understanding is that pumping heat out of the permanent magnet motors is not a problem.
The rotor does not have the same self heating problem as the AC induction ones, that's for sure. I think one of the track mode reviews mentioned using the pack as a heat sink for the drive unit. There is a lot of thermal mass there, especially when pre-cooled.
So annoying to not have access to the data...
Krash
Data Technician
Fantastic discussion. I wonder if anyone has attempted to track a Model S with the post June 2017 DU01 (or smaller DU00) drive units that are rumored to have the new Model 3 inverters. Or if anyone has done a performance autobahn run of the same drive units to see if the thermal limiting differs.
The real limiter is the lack of a traditional radiator and using the ac and heat exhcangers to cool things down. A large radiator isnt needed for 99% of EV usage scenarios and would reduce aero and range so it makes sense that Tesla left it out.
I don't follow, are you referring to size? Teslas have real radiators, the 3 has what looks like a nice sized one reclined for more area. AC is used for additional cooling if ambient is insufficient.
I got an AWD. 1.5 months old with 2k miles on it. This car is fast! I just hand times from complete stop. I have 50% battery at 158 miles, it’s 43 degrees Fahrenheit outand I drove about 8 miles to warm it up. Did a legit 4.1 sec. I’m wondering what I really got......
QUOTE="yul sam, post: 3070115, member: 39063"]I posted this in the Canada forum. I think it might be of interest to the general audience
On Monday I went to the Montreal dealership for delivery of my P3D-, MSM, 18" aeros, white interior. There were 5 or 6 M3's inside the showroom awaiting delivery, and I went to the one that fit my order, and the vin was mine. The car was pristine inside and out, very well detailed and waxed. The paperwork went quickly and smoothly, and the car appeared in my app.
That’s when I noticed that the red line under Dual Motor was missing in the app. I checked and it was also missing on the car’s screen. I also noticed that the choices for Acceleration in the car’s settings were Chill and Standard (Instead of Sport).
I brought this to the attention of the DS, and pretty soon, several technicians were checking the car and their computers, and they got in touch with engineering in the US. They confirmed that the car was AWD and promised a quick fix. It took about 30 minutes for the red lines to appear, and Standard also changed to Sport, and soon I was on my way. I come from a 70D model S, and had taken delivery of my daughter’s RWD back in June and drove it around for a couple of weeks, and this car’s acceleration was totally something else.
Yesterday I did a couple of runs (in opposite directions) with my G-tech RR from 2008, and got 3.3 and 3.4 seconds 0-60. I looked at the old runs from back then, my V10 M6 BMW with launch control was good for 4.45-4.6 seconds. I am in awe, and can't seem to wipe the stupid grin from my face.
Was the car a regular AWD or built with "performance binned" motors and drives? No way to know!
Was the car unlocked to Performance with only the screen settings missing, or was it 100% AWD? Again no way to know.
One thing I know is that the car is still AWD in my "view car details" page on my Tesla account.
I had a great delivery experience, my new car is perfect, not even a minute blemish, and everything works, and it way exceeds my expectations in build quality and performance. Also all the other cars that I checked while waiting were similarly immaculate. I simply cannot understand the horror stories from other delivery locations.
[/QUOTE]
QUOTE="yul sam, post: 3070115, member: 39063"]I posted this in the Canada forum. I think it might be of interest to the general audience
On Monday I went to the Montreal dealership for delivery of my P3D-, MSM, 18" aeros, white interior. There were 5 or 6 M3's inside the showroom awaiting delivery, and I went to the one that fit my order, and the vin was mine. The car was pristine inside and out, very well detailed and waxed. The paperwork went quickly and smoothly, and the car appeared in my app.
That’s when I noticed that the red line under Dual Motor was missing in the app. I checked and it was also missing on the car’s screen. I also noticed that the choices for Acceleration in the car’s settings were Chill and Standard (Instead of Sport).
I brought this to the attention of the DS, and pretty soon, several technicians were checking the car and their computers, and they got in touch with engineering in the US. They confirmed that the car was AWD and promised a quick fix. It took about 30 minutes for the red lines to appear, and Standard also changed to Sport, and soon I was on my way. I come from a 70D model S, and had taken delivery of my daughter’s RWD back in June and drove it around for a couple of weeks, and this car’s acceleration was totally something else.
Yesterday I did a couple of runs (in opposite directions) with my G-tech RR from 2008, and got 3.3 and 3.4 seconds 0-60. I looked at the old runs from back then, my V10 M6 BMW with launch control was good for 4.45-4.6 seconds. I am in awe, and can't seem to wipe the stupid grin from my face.
Was the car a regular AWD or built with "performance binned" motors and drives? No way to know!
Was the car unlocked to Performance with only the screen settings missing, or was it 100% AWD? Again no way to know.
One thing I know is that the car is still AWD in my "view car details" page on my Tesla account.
I had a great delivery experience, my new car is perfect, not even a minute blemish, and everything works, and it way exceeds my expectations in build quality and performance. Also all the other cars that I checked while waiting were similarly immaculate. I simply cannot understand the horror stories from other delivery locations.
At 4.1 sec, I think you got an AWD. Since I started this thread, the parts manual for M3 came out. AWD and P- have the same parts, so you are a software unlock away from a Performance M3.
[/QUOTE]
After tens of thousands of deliveries, they must be finally getting the details figured out.
Msjulie
Active Member
My car doesn't say Performance on the website but it does have red line on the screen - parts are the same per Elon, the Performance are just special-magic-selected. Well maybe they are, maybe they aren't - your experience suggests otherwise as does another couple folks who had the same my Performance is only an AWD car thing...
My point is, I ran a 4.1 with 50% cold battery and it was 42 degrees outside. What’s this car going to do with close to 100% charge and warm battery in warm weather? Sub 4 should be very easy
Knightshade
Well-Known Member
You said you "hand timed" it- which is pretty worthless for precise measurement.
So unless you've got a vbox or draggy (or similar) result you didn't run a 4.1 with anything.
For official timing sure. Im pretty good with a stopwatch. No way I was off either side of that .1 sec +/`-. Point is....this car is much faster than 4.5 sec/ 0-60. Also, even running that , It was obviously slower than it was only days earlier with a full charge and warmer weather. Im assuming there is a thread here somewhere that explains performance drop off in cold conditions and also with varying stat of charge.
The P does have different breaks/calipers, and rides a little low. As for the motors I hear they are the same. I did read a thread where a guy bought a P but had AWD and nothing on the cars computer saying it was a P. He called tesla and after a download, he had a P with all the extra performance.
