Will AWD Model S make current P85 and P85+ seem slow by comparison?

[Olle]

There is only one 'correct' way to increase the power of battery pack - make it bigger. Power increases with capacity.
Will P+ be able to harvest all of it? Probably not.

Who decides what the "correct" way of increasing power is? Was the MS 40 not made correctly having 235 hp?

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AFAIK Model S power is battery limited. So adding an other motor doesn't add power.

Yes that is what I heard too. That is why I wrote "I am speculating that they will... ... increase battery power" to make the P and PAWD faster than SAWD

I am even starting to think that the reason for the current 470 hp DU in the P was just this, to not need to redesign it when the SAWD arrives. Instead redesign the battery pack. Like they changed the battery up from 90kW charging when the 120kW superchargers arrived.

 

[rogbmw]

"Yawn".........who knows. Speculation is just that...fun speculation. Guess we will just have to sit back and enjoy the show and see what happens

 

[Gizmotoy]

Has anyone who has been to the drag strip in a P85 launched without wheel spin with traction control disabled? If it doesn't spin the wheels on launch at the strip, AWD isn't going to do much to improve the 0-60. I was under the impression that with sticky summer tires there wasn't any wheel spin, so the acceleration wasn't traction-limited.

 

[WarpedOne]

Who decides what the "correct" way of increasing power is?

CFO. He says the correct way of doing things is the least expensive one.
When one has access to billions of cells X at lowest possible price point because of order volume he increases the power by increasing the capacity using more of those same cells. When he decides to increase the capacity he does not mind increasing the power.
Using cells with higher power would:
- decrease capacity
- superlinearly increase the cost because of smaller order

Was the MS 40 not made correctly having 235 hp?

No. Hence it was axed.

AFAIK Model S power is battery limited. So adding an other motor doesn't add power.

MSP is battery power limited between 42 and 73 mph. Under 42 and above 73 mph it is limited by inverter/motor.
Second inverter/motor would increase performance below 42 and above 73 mph.

Like they changed the battery up from 90kW charging when the 120kW superchargers arrived.

120kW superchargers were validated against B battery pack. They didn't bother spending resources on testing against A packs there were already sold out.

 

[Gizmotoy]

MSP is battery power limited between 42 and 73 mph. Under 42 and above 73 mph it is limited by inverter/motor.
Second inverter/motor would increase performance below 42 and above 73 mph.

Interesting. That's actually the first I've heard that, and I spend way too much time here. Those numbers sound pretty exact, so presumably there's supporting documentation somewhere? Can you link it? I'm interested to read about how they tested it all.

 

[Olle]

Does anybody know if the much talked about battery power limit is programmed to be 310kW for P85 or if this is the physical limit of a full flow through battery and inverter?

If we are talking about full flow, the car would be significantly slower with low charge (350 V) compared to fully charged (400 V). Or not?

 

[Matias]

A bit off topic, but from this picture one can see, that adding front motor below frunk is not trivial task.

 

[WarpedOne]

Interesting. That's actually the first I've heard that, and I spend way too much time here. Those numbers sound pretty exact, so presumably there's supporting documentation somewhere? Can you link it? I'm interested to read about how they tested it all.

I explained it here

Does anybody know if the much talked about battery power limit is programmed to be 310kW for P85 or if this is the physical limit of a fully closed circuit?

It is programmed at a level that is not to damaging to the cells.
MS60: 225 kW / 60kWh = 3,75C
MS85: 270 kW / 85kWh = 3,17C
MSP: 310 kW / 85kWh = 3,65C

The battery in MS60 sees the highest stress. There are also other dirty details of electronics that play a role in "max power play" but the battery is primary driver and limiter.
Short circuit power is in the realm of few hundreds C, around 10.000 HP (most of them expressed thermally).

 

[Olle]

The battery in MS60 sees the highest stress. There are also other dirty details of electronics that play a role in "max power play" but the battery is primary driver and limiter.
Short circuit power is in the realm of few hundreds C, around 10.000 HP (most of them expressed thermally).

I didn't mean short circuiting the battery of course, but closed circuit through battery and motor. (Ok it s not really closed because it is inverted to AC but whatever max you can get)

 

[Matias]

I explained it here

So would bigger reduction ratio increase power below 40 mph?

 

[brianman]

Does anybody know if the much talked about battery power limit is programmed to be 310kW for P85 or if this is the physical limit of a full flow through battery and inverter?

It is programmed at a level that is not to damaging to the cells.
MS60: 225 kW / 60kWh = 3,75C
MS85: 270 kW / 85kWh = 3,17C
MSP: 310 kW / 85kWh = 3,65C

If you're saying that Tesla puts a software limit at these levels such that you can not "spend" more than that, then there's a bug in the software or a bug in your assertion. I have lots of telemetry from the car saying I've exceeded 310 kW with regularity.

 

[Olle]

If you're saying that Tesla puts a software limit at these levels such that you can not "spend" more than that, then there's a bug in the software or a bug in your assertion. If have lots of telemetry from the car saying I've exceeded 310 kW with regularity.

Just how much power does a Tesla Model S produce? - YouTube

They ran it on dyno and got 428 hp or 315-319 kW on the wheels. Truly a bug in the 310 kW software limit...

 

[brianman]

They ran it on dyno and got 428 hp or 315-319 kW on the wheels. Truly a bug in the 310 kW software limit...

Last year, my record high was 363 kW on drive unit #1. I haven't looked through the logs yet this year on #3 (whereas #2 peaked in the 340s IIRC).

 

[WarpedOne]

So would bigger reduction ratio increase power below 40 mph?

Yes.

If you're saying that Tesla puts a software limit at these levels such that you can not "spend" more than that, then there's a bug in the software or a bug in your assertion. If have lots of telemetry from the car saying I've exceeded 310 kW with regularity.

It is not a bug in the software nor in my assertion - it is a 'bug in published specs' and/or their accordance with reality.
Did they change "official weight" of the car since start of production? No.
Did Elon 'bragged' about lower weight of newer cars? He did.

Do you get more than 310kW when under say 10% SOC?

 

[Olle]

I get yellow dotted lines way under 310kW at 10% SOC, 80kW yellow line if I remember correctly

 

[brianman]

Do you get more than 310kW when under say 10% SOC?

I'll probably never know this answer. The "zero rated" mark seems to be ~6-7% SOC for me. When I'm at "<= 4% SOC above zero rated", I'm never pushing the car. Well, I might be literally pushing the car but not pushing the accelerator hard.

 

[Olle]

Last year, my record high was 363 kW on drive unit #1. I haven't looked through the logs yet this year on #3 (whereas #2 peaked in the 340s IIRC).

do you get the milling sound or what's wrong with your drive units?

 

[brianman]

It is not a bug in the software nor in my assertion - it is a 'bug in published specs' and/or their accordance with reality.

I disagree with this characterization. The published specs talk, as I understand it, are about the "promised performance minimums". Nobody (that I know of) complains about getting 25 Mb/s when they pay for 20 Mb/s. Do you think anyone ever says: "I do better than the advertised 0-60; I guess I should return my car because the advertising is too conservative".

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do you get the milling sound or what's wrong with your drive units?

1. Milling (motor we think) then "restart car" drama (inverter IIRC).
2. Car stalled and reported Traction Control, Stability Control and other error messages (PEM/circuitry issues we thought at the time).

Neither had a formal follow-up e-mail or whatever explaining the diagnosed issue. I believe it's policy that usually they don't tell us.

So far #3 seems good. I pray it lasts long beyond mile 50,001 ... or that it gets replaced before mile 50,000.

 

[Matias]

Yes.

So AWD Model S could have better acceleration, even if max power would stay unchanged, if motors would use different reduction rations?

 

[In2oil]

how about added weight.! The Current TESLA model S has no lack of grip.. It won't be much faster if at all. The only concern I have with the all wheel drive is the extra power required for the 2 motor.. I think the range will suffer dramatically. Still i would be interested in swapping my current ride for one. Anything TESLA does is awesome.

I love my current TESLA.