I really wish someone with a P90D *without* L would log the "power" field from REST. It might give us an indication i the IR is less or significantly less than the P85D. If it is, then even the P90D (without L) will pull more power than the P85D.
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P85D Ludicrous Pre-Order Upgrade Available 9/25/15
- Thread starter Whiplash
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- Driving Dynamics Model S
I really wish someone with a P90D *without* L would log the "power" field from REST. It might give us an indication i the IR is less or significantly less than the P85D. If it is, then even the P90D (without L) will pull more power than the P85D.
tstafford
Active Member
Yep. This is the only way to read it and have it make sense mathematically. So unless this is a typo by Tesla I'm out. There's no way I'm paying $7000 for a .2 second improvement in 30-60 time and no other performance benefit.
I'm also becoming irritated that after speaking to Tesla people a few times I ultimately went forward with my P85D delivery rather than cancel the order and get the P90DL. This would have cost me $2500 in the form of a lost deposit. But I would have gotten what I wanted.
Darn it.
While it might not be necessary I'll mention as a disclaimer that I have no inside contacts at Tesla or access to any internal information so I don't know more than what I'm going to mention. Also as a note to Tesla employees reading this, the people I talked to were very quiet and very careful not to answer my questions when I asked for more detail.
When I upgraded to the P90DL, I met someone very familiar with the fuse and indicated there is more room above 1500amps, which if true means there's still room for improvement.
When I was borrowing a P85+, I ran into someone that works at the factory and he asked me about how I liked the car. I told him I ordered a P90DL after driving a P85D. So he was aware I was familiar with what I was getting and he said "oh man, just wait...". When I asked what he meant he said he couldn't say a word more. So it clearly wasn't about just receiving my car.
This makes me believe that the improvements that were made in the P90DL extend beyond what we currently know about. I've hit 2.81s 0-60 and max power I've logged was 457kW, which isn't 1500amps unless the power output in the streaming API is read beyond the fuse and there is a lot of loss. If I was at 400v at the time that's only 1142 amps, but I don't have overlapping streaming and REST data to know. I have some free time this weekend so I'll go out and see what info I can gather.
When I upgraded to the P90DL, I met someone very familiar with the fuse and indicated there is more room above 1500amps, which if true means there's still room for improvement.
When I was borrowing a P85+, I ran into someone that works at the factory and he asked me about how I liked the car. I told him I ordered a P90DL after driving a P85D. So he was aware I was familiar with what I was getting and he said "oh man, just wait...". When I asked what he meant he said he couldn't say a word more. So it clearly wasn't about just receiving my car.
This makes me believe that the improvements that were made in the P90DL extend beyond what we currently know about. I've hit 2.81s 0-60 and max power I've logged was 457kW, which isn't 1500amps unless the power output in the streaming API is read beyond the fuse and there is a lot of loss. If I was at 400v at the time that's only 1142 amps, but I don't have overlapping streaming and REST data to know. I have some free time this weekend so I'll go out and see what info I can gather.
lolachampcar
Well-Known Member
I think the wise thing to do is to let the dust settle on P90DL 0-60 (seems to be ok at 2.8 or so - verified by a few people) and 1/4 mile times (may be a problem here as no one has yet to see tens) in addition to waiting for and documenting performance of the P85DL. Once we have repeatable results across multiple owners we will know exactly what Tesla is capable of delivering in the now timeframe.
As for the (oh squirrel) there is more coming, I think I will stay 100% focused on what Tesla is doing today and try to make the most informed decision possible WRT moving forward with the P85DL upgrade.
As for the (oh squirrel) there is more coming, I think I will stay 100% focused on what Tesla is doing today and try to make the most informed decision possible WRT moving forward with the P85DL upgrade.
MarcG
Active Member
Lola, would love to hear your thoughts on the Tesla order page verbiage regarding 0.2 sec improvement for BOTH 0-60 mph and 1/4-mile times.
Brit4864
Member
lolachampcar
Well-Known Member
MarcG,
SNAFU seems to be Tesla's motto. My gut tells me there will be very little difference between the 85DL and the 90DL provided Tesla does not intervene in software. Given all the confusion, I want real world numbers before I plunk down the (rest of my) cash
I would not base a purchase decision on the information Tesla is providing.
SNAFU seems to be Tesla's motto. My gut tells me there will be very little difference between the 85DL and the 90DL provided Tesla does not intervene in software. Given all the confusion, I want real world numbers before I plunk down the (rest of my) cash
I would not base a purchase decision on the information Tesla is providing.
Jallum.pa.us
Member
Let me take a stab at unpacking this, then.
The motor used to be the performance limiting part. Then they put two of them into the car, and around the same time, they figured out how to get more out of them by screwing around with the power electronics (the increases we've been seeing in "motor power" ratings.) Now, we have a situation where there is more motor than we have juice to run them with (the P85D.) Since the "Ludicrous" option is available for it now, we know that the limitation wasn't imposed by the batteries themselves. It's the dumb, 1300A thermal fuse and the metals present in the contactors (these parts just happen to live in the battery pack.) Tesla has made a big deal about the way the new fuses work - they're current sensors wired up to a controller that can cut the circuit via pyro charge (Very cool, they deserve to be proud!) The upshot is, that once added to the system, the fuse can be reprogrammed to blow at whatever level of current they choose. Bump it to 1500A, and things can get ludicrous. Figure out that it's safe to push it further, and I dunno... "Maximum Plaid?"
My bet is: The wiring in the older, Revision "E" packs that come in all the P85D cars will be of sufficient gauge to handle currents at-or-near 1500A for short periods, but will not be sufficient to handle whatever they deem to be the next level for those on the 90kw packs. My wild-ass-guess is that those packs are made of "sterner stuff" and we'll see software in the coming months that will put the press back into a froth right about the time the current "ludicrous" news dies down.
The motor used to be the performance limiting part. Then they put two of them into the car, and around the same time, they figured out how to get more out of them by screwing around with the power electronics (the increases we've been seeing in "motor power" ratings.) Now, we have a situation where there is more motor than we have juice to run them with (the P85D.) Since the "Ludicrous" option is available for it now, we know that the limitation wasn't imposed by the batteries themselves. It's the dumb, 1300A thermal fuse and the metals present in the contactors (these parts just happen to live in the battery pack.) Tesla has made a big deal about the way the new fuses work - they're current sensors wired up to a controller that can cut the circuit via pyro charge (Very cool, they deserve to be proud!) The upshot is, that once added to the system, the fuse can be reprogrammed to blow at whatever level of current they choose. Bump it to 1500A, and things can get ludicrous. Figure out that it's safe to push it further, and I dunno... "Maximum Plaid?"
My bet is: The wiring in the older, Revision "E" packs that come in all the P85D cars will be of sufficient gauge to handle currents at-or-near 1500A for short periods, but will not be sufficient to handle whatever they deem to be the next level for those on the 90kw packs. My wild-ass-guess is that those packs are made of "sterner stuff" and we'll see software in the coming months that will put the press back into a froth right about the time the current "ludicrous" news dies down.
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Yep you may be right. The current P90DL is limited at high speed and this is supported by the recent quarter mile speed obtained by Fiks with 116 MPH.
I fear they may be doing this so there won't be much of a difference to an upgraded P85DL so they don't piss off P85D owners further and sell upgrades.
Then in 6 months the free OTA P90DL upgrade will come and improve the high speed performance.
I really hope I am wrong.
Probably best to wait it out. Elon did say that it would be possible to upgrade the battery to a 90 with ludicrous.
I would rather pay 20-30 grand and get 10.9 and high speed than 7500 for 2.9 0-60.
Don't want to trade my P85D since it has the sport suspension.
This where more information would help us make a decision. I really don't think Tesla cares.
I think there's a little more going on. I believe the differences between the 85 and 90 are the anodes which help hold and deliver the charge and seem to hold a higher voltage for longer in use. These batteries don't seem to be static in that if you draw an amount of current from them, over a short time the voltage will drop and we probably all know that the power is volts x amps, so Ho,ding that voltage gives better sustained power output. My suspicion is with the 85, the anodes/battery can't deliver the sustained power (even for very short periods) to match the 90. I imagine the 90D will have an easier time delivering its performance compared to a P85D which is a worry for Tesla as it closes the gap.
The new fuse is interesting and reminds me of my days modelling 400kv electricity cables. We introduced a dynamic rating that basically said the recent historic load conditions created a temperature profile and you could load the cables up pretty high for short periods so long as you kept the temperature profile below a level. In effect you are not limited to a specific current, you are limited to a temperature. The old safe way was to pick a current that would mean you never reached the temperature. The new way which deliver a lot more short term capacity was to use a dynamic limit that would blow the temperature if sustained for a given period - the shorter the period, the higher the limit. I imagine the new tesla fuse is doing this type of thing and for safety sake or other limiting factors you still have an max upper limit and the management software is otherwise keeping the temperature down.
So the 90 helps retain more voltage
The fuse helps deliver peak current
you need both to get max performance and both change quickly
The nearest ICE analogy I can think of is a turbo which is almost the exact opposite, floor the car at low revs and there's no boost, as the revs slowly climb the boost increases and so does the power that then increases the speed which increases force if sir into the engine and the boost making it climb quicker. The dynamics of the whole system constantly change.
Now I understand some of the tail off at higher motor speed is because the motor characteristics change as it spins faster. My days of study on motor performance and back emf etc are too far back to be certain, but it's this back emf test deteriorates the higher speed performance. So have they got the gearing wrong? Would you be happier with a car that did 0-60 in 4s not 3s but had more go above 60mph by using longer gearing? It's a complicated juggling game as the performance changes much more significantly over time and speed than a petrol car. The tesla sweet spot is 0-60 maybe even only 0-40 and that grabs drag racing headlines. That's not to say it's not quick above, these things are all relative. The ICE cars you see tend to have sweet spots well above that which is why they all catch the tesla up eventually. Everyday driveability you could argue tesla have it right, I think I'd prefer the best performance to be at a little higher speed in the tesla.
The new fuse is interesting and reminds me of my days modelling 400kv electricity cables. We introduced a dynamic rating that basically said the recent historic load conditions created a temperature profile and you could load the cables up pretty high for short periods so long as you kept the temperature profile below a level. In effect you are not limited to a specific current, you are limited to a temperature. The old safe way was to pick a current that would mean you never reached the temperature. The new way which deliver a lot more short term capacity was to use a dynamic limit that would blow the temperature if sustained for a given period - the shorter the period, the higher the limit. I imagine the new tesla fuse is doing this type of thing and for safety sake or other limiting factors you still have an max upper limit and the management software is otherwise keeping the temperature down.
So the 90 helps retain more voltage
The fuse helps deliver peak current
you need both to get max performance and both change quickly
The nearest ICE analogy I can think of is a turbo which is almost the exact opposite, floor the car at low revs and there's no boost, as the revs slowly climb the boost increases and so does the power that then increases the speed which increases force if sir into the engine and the boost making it climb quicker. The dynamics of the whole system constantly change.
Now I understand some of the tail off at higher motor speed is because the motor characteristics change as it spins faster. My days of study on motor performance and back emf etc are too far back to be certain, but it's this back emf test deteriorates the higher speed performance. So have they got the gearing wrong? Would you be happier with a car that did 0-60 in 4s not 3s but had more go above 60mph by using longer gearing? It's a complicated juggling game as the performance changes much more significantly over time and speed than a petrol car. The tesla sweet spot is 0-60 maybe even only 0-40 and that grabs drag racing headlines. That's not to say it's not quick above, these things are all relative. The ICE cars you see tend to have sweet spots well above that which is why they all catch the tesla up eventually. Everyday driveability you could argue tesla have it right, I think I'd prefer the best performance to be at a little higher speed in the tesla.
sillydriver
Member
Jallum and JonG -- both very good comments, I think. Perhaps what P90DL cars are doing now is not as quick as they will be after a further software change that the P85DL hardware cannot benefit from. However if the upgraded P85DLs can achieve essentially the same bursts of passing power that the P90DL owners are reporting now, that would be enough for me to want to go through with the upgrade. JonG, if you are right and the ultimate limiting factor for the P85DL is faster temperature build-up over time (rather than Jallum's idea of instant current limits from internal wires) then that would still be okay for me. It would mean the P85DL would never be able to run as hard as the P90DL for the whole 11s it would take to do a quarter mile run from a standstill, but what I care about is the 4 - 5s run from 60 MPH to 90 or 100. Under JonG's theory the P85DL might still be nearly as fast as the P90DL, because in that shorter time its temperature might not hit the limit. All very complicated and speculative, I admit.
A friend just took delivery of a P90DL. He has the + suspension. So apparently the + is back.
Jallum.pa.us
Member
Actually, JonG and I are saying the same thing with respect to the 85kw packs's potential limitations after upgrade. His description is much more thorough.
lolachampcar
Well-Known Member
The only caveat I would add about 85/90 pack differences is that, typically, increases in capacity for endurance cells provide a small bump in high load capability. But, by the nature of endurance cells, that lower source impedance is nowhere near a linear relationship with capacity increase. Put differently, I'm not so sure the increased capacity of an endurance battery will give a proportionate increase in surge capability.
Of course, I'm on the outside just guessing. I do not think Tesla is interested in or capable of providing detailed information at this stage in the game. They likely do not know all the answers just yet and, if they did, why on earth would they share what they know with the throngs lining up to beat them over the head with any information they do provide?
The best for me is wait and see what happens in the real world then make my call (without considering what OTA update might be coming down the road - that will just be gravy).
Of course, I'm on the outside just guessing. I do not think Tesla is interested in or capable of providing detailed information at this stage in the game. They likely do not know all the answers just yet and, if they did, why on earth would they share what they know with the throngs lining up to beat them over the head with any information they do provide?
The best for me is wait and see what happens in the real world then make my call (without considering what OTA update might be coming down the road - that will just be gravy).
tstafford
Active Member
I second this. All we can really do now is wait until the first upgrades are done at Fremont and get the numbers.
lolachampcar
Well-Known Member
I'm seeing the writing on the wall.....
Dragtimes P90D Ludicrous 0-60mph and 0-100mph video - Page 6
Dragtimes P90D Ludicrous 0-60mph and 0-100mph video - Page 6
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