Taycan video with some useful information

[Youtube]7BB0S6hmM0s[/Youtube]

Decent comparison with the Tesla MS-MX

[Youtube]-pJlzLnsTSY[/Youtube]

Interesting that it uses an 800V battery and a two-speed rear axle: https://www.caranddriver.com/news/a28903274/porsche-taycan-transmission/

Although the rear axle is not always connected and when it is it spends most of its time locked in high gear, only changing down for high speed launches. This does echo the prevailing opinion on this forum that the usefulness of a lower ratio is only apparent at relatively low speeds and the crossover point where you get better acceleration in the high ratio occurs quite rapidly. I suspect the inclusion of this transmission is only due to Porsche prioritising achieving the most rapid 0-60 acceleration they could (and consistently at differing states of charge).

Yeah, the 2-speed caught my eye too. Of course they wanted a 160-MPH top speed, so that shifts quite a bit of the design requirements. I've been up to 100-MPH several times, and stuff just happens too fast for me at that speed. That validates some things I've been wondering.

I would be quite content with a 100-MPH top speed, using a "one speed" (maybe 120?), but of course, Germany has the autobahn. Whether a vehicle "needs" a 2-speed or not is a discussion that will continue (for my type pf driving, I do not need it), but...I am very curious about seeing how Porsche designed their 2-speed...

More details ,..some of which do not make sense ?
IE.. double the amps to the motor, but only 10% more power ??
https://www.motorauthority.com/news/1124886_2020-porsche-taycan-turbo-vs-turbo-s-electric-car-battery-tech-specs-and-pricing

While the Taycan Turbo and Turbo S have similar rear powertrains, the front motor carries an inverter rated at 600 amps on the more-powerful car, but only 300 amps on the Turbo. That means the Turbo S can simply draw more power from the car’s 93-kwh battery pack and deliver it to those wheels.
Specifically, the Turbo’s front-motor maximum output is 175 kw (235 hp), while it’s 190 kw (255 hp) on the Turbo S.

Launch control

In addition, a Launch Control mode is available exclusively on the Turbo S, providing a temporary “overboost” that raises the maximum torque delivered by both motors for 2.5 seconds. So the 335-kw (450-hp) rear motor's output rises from 406 to 450 pound-feet, and the front from 295 to 325 lb-ft.

That delivers maximum possible acceleration from a standing start without spinning the wheels. We experienced it, and it thrusts passengers back into their seats just as a high-performance Tesla does. Porsche claims the Taycan can deliver consistent maximum-power runs dozens of times, unlike competitors whose software dials down the maximum acceleration as powertrain heat rises and the battery’s state of charge declines.

Both versions use an unusual two-speed gearbox for the rear motor, unlike almost all other electric cars today that have a single-speed transmission. In Sport mode, the control software keeps the gearbox in the lower gear for faster acceleration, while Normal driving mode prioritizes the higher gear under most circumstances. Range mode, meanwhile, keeps the car exclusively in second gear.

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Hilarious video
[Youtube]JPdxNZf57F0[/Youtube]

Good comparison with Tesla MS:
https://podcasts.apple.com/us/podcast/tesla-daily-tesla-news-analysis/id1273643094#episodeGuid=http%3A%2F%2Ftechcastdaily.com%2F%3Fp%3D1021

Hillhater said:

More details ,..some of which do not make sense ?
IE.. double the amps to the motor, but only 10% more power ??

Click to expand...

Best guess it's extra phase phase amps to boost low down torque for launching into the 0-60 sprint but the party is largely over by the time you hit ~50% motor speed where peak power is measured.

My eye twitches a little each time I hear the phrase "Taycan Turbo"

It's cool, but a Turbo Porsche it most certainly is not.

Also, coupes have 2 doors. Not 4, not 5, but 2. I wish automakers would stop attempting to rewrite the dictionary.

I applaud the presentation of the new Taycan. Good for Porsche. In fact...they produced the electric/gas hybrid in Paris in the year 1900. However...walk into your local Porsche dealer with a blank check, and try to buy one...

Punx0r said:

Hillhater said:

More details ,..some of which do not make sense ?
IE.. double the amps to the motor, but only 10% more power ??

Click to expand...

Best guess it's extra phase phase amps to boost low down torque for launching into the 0-60 sprint but the party is largely over by the time you hit ~50% motor speed where peak power is measured.

Click to expand...

They certainly do boost the torque...as they report later in that article...

a Launch Control mode is available exclusively on the Turbo S, providing a temporary “overboost” that raises the maximum torque delivered by both motors for 2.5 seconds. So the 335-kw (450-hp) rear motor's output rises from 406 to 450 pound-feet, and the front from 295 to 325 lb-ft.

Click to expand...

But again , its only a 10% increase ??....fron 2X the amps ??
...... I dont think we are getting the full story yet.

Yeah, I don't know. Unless that's the torque at peak power rather than peak torque.

Another article with much more tech detail...very informative of the design decisions and limitations..
https://jalopnik.com/an-extremely-detailed-look-at-the-porsche-taycans-engin-1837802533

The Taycan’s battery pack consists of 33 cell modules, each of which contains 12 individual 64.6 amp-hour LG pouch cells. They are arranged such that half of the cells, 198, are in parallel with the other half. The big number that’s been thrown around for years now is “800,” as it’s a rather high system voltage for an EV.

In the case of the Taycan, the actual voltage sits somewhere between 610 (depleted) and 835 volts (when full), with a nominal voltage of 723 volts. Maximum energy content is 93.4 kWh,

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Rear transmission with planetary gearset and two ratio gearing.16:1, and 8.05:1


Front trans’ with dual concentric planetary gearing and 8.05:1 reduction.

This is one of the most impressive things:

https://www.motor1.com/news/366038/porsche-taycan-nardo-endurance-run/

24 hour endurance run, 2100miles covered at an average speed of ~89mph.

That's driving at between 121-134mph and stopping to recharge when needed. The range and charge time used for the stunt isn't given but normally 15 minutes charge gives ~250 miles of range.

"EVs won't work because they take too long to charge!" 8)

When you double the amps, but only get 10% more power, I suspect the motor was at the point of saturation. After magnetic saturation is reached, I'm told that additional amps above that will add some power, but...it adds only a small amount of power, in exchange for a lot of waste-heat.

I believe this is one of the reasons to add the complexity and cost of a motor cooling system.

A great article with some very interesting details. Standout for me is the large number of additional components when compared to the Tesla drivetrain. In particular comparing Taycan to the construction of the Model 3 there's a lot of additional complexity.

The transmission, multi plate clutch, actuators are the obvious ones, but there's a few more that the article touched on too - the addition of an onboard DC-DC charging converter to step up the commonly available 400vdc fast charging to the packs configuration of 800v is another relatively expensive component to produce and package.

The cited benefit of moving to an 800v architecture are quite redundant - the only area in which conductive losses would factor is in the fairly long HV cabling from the BMS/pack output area on the top to the high mounted inverters on the drivetrain modules. By making better packaging decisions the length required can be dramatically reduced, offsetting the fairly small amount of copper required to deal with half voltage/double current. They also openly admit they had to develop the electronics essentially from scratch as nobody else was doing 800v components - that's a big cost for questionable reasons...

Other area of interest is the thermal management of the battery - large form factor prismatic modules with a single sided cooling plate seems like a recipe for large temperature variation relative to each and every cell having contact with a cooling loop.

I do really like the layout of the front drivetrain module with the axle actually running THROUGH the rotor. Still a lot more complex than the Tesla equivalent, but it's elegant having the motor co-axial with the output.

I think the 800 V DC operating voltage is mainly for the benefit of the DC fast charger, not the battery receiving it.
It's a pretty convenient voltage for IGBTs but you can get equally good IGBTs to manage ~380 V DC.

I'm interested in the cooling system. Is that a cooling plate beneath all the modules? And if so, is it running coolant, or is it running refrigerant? If the latter, it would be in the same camp as the Renault Zoe and the BMW i3.

That 800v system may also help with thermal control of the pack, ..and motors , inverters ?.
For any given kW draw on the pack, theoretically they will be half the current draw, which should reduce internal heat generation ?
Notice that the inverters are 600a max, and the rear motor is 340kW max (420A @ 800 volts ?)
.....Front motor, 190kW, 240A ?....approx.
So a total of 530kW, 660A......way less than Tesla ( 1500amp pack fuse reported ?)
On their 129Ah pack, that is only a 5C load on those LG cells
Add to that , the 16:1 low gear ratio, low speed motor load should also be less than the 8:1 “range” ratio, ..( or the 9.7:1 ratio used in the Tesla )....
I am surprised that the Taycan isnt faster to 100km/h with that lower gearing....
......but maybe it because of its 5100lb weight

It's possible there are thermal advantages from the higher voltage relative to other inverter tech available to Porsche but it can't be assumed.. generally higher voltage capable silicon has a proportional increase in resistance. There are 'sweet spots' where system efficiency peaks and perhaps 800v won out, but I don't think it could be by enough to justify all the extra development and components required. I think it was done primarily for marketing wank.

We can say with confidence though that the Tesla inverters are more efficient - if they weren't then Porsche would parade that fact front and center. SiC is a big advantage that nobody else seems close on.

Double the amps is no disadvantage if your pack is configured with half the IR, nor if packaging means your HV connections are a few inches away from the final destination...

Ohbse said:

.....
Double the amps is no disadvantage if your pack is configured with half the IR, nor if packaging means your HV connections are a few inches away from the final destination...

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But we know the “S”has always had an issue with thermal build up in their pack (and the motor.)
Those issues are magnified at higher power levels (amps !)

Hillhater said:

But we know the “S”has always had an issue with thermal build up in their pack (and the motor.)
Those issues are magnified at higher power levels (amps !)

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Induction motors are capable of huge burst power but have inherent thermal limitations with rotor cooling, the model S is a well optimised system for what it was designed for, motor being the limiting factor for sustained performance. New model setting records at Laguna Seca and no doubt the ring doesn't have that rotor cooling limitation running very efficient pmsm with a significant reluctance component.

Pack heating is down to a chemistry compromise, there's no point in having a pack that's capable of 2x the power the vehicle requires if it means giving up energy density or cycle life. Since 2012 there have been continuous improvements in module capability, like with model 3 performance I don't think pack heating will be a weak spot

Tesla's cell topology is superior to porsches with regards to cooling potential - that's not even a debate, just fact... Every cell is in contact with a cooling element compared with only indirect cooling for majority of each taycan module. Porsche might generate less pack heating due to lower IR (compared with current model S) but they gave up a lot to achieve that, worse range, higher weight, likely some longevity. Clearly the 'plaid' preproduction models have no major heat limitations.

Also pack heating in a hypothetical 100kwh pack terminated as 400v is identical (for purposes of this discussion anyways) as one at 800v. Amps are halved, but your number of series connections (and thus resistance) is doubled.

Ohbse said:

...Tesla's cell topology is superior to porsches with regards to cooling potential - that's not even a debate, just fact... Every cell is in contact with a cooling element compared with only indirect cooling for majority of each taycan module. Porsche might generate less pack heating due to lower IR (compared with current model S) but they gave up a lot to achieve that, worse range, higher weight, likely some longevity. Clearly the 'plaid' preproduction models have no major heat limitations...

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That superior topology was obviously born of necessity, and even then proved to be inadequate.
Porsche seemed to have thought out their system to avoid that situation.
Interesting that you know the production plaid has no heat issues ?.... you have a crystal ball ?

Based on my experience and research on battery thermal management, Tesla has done a very good job with the system they are working with, but it is by no means the best. It has been optimised for the task (driving a 2 ton saloon car down the road a long way) and it does that very well.

But more superior cooling means more complications, more weight, less room for energy storage and so on. If you choose more expensive pouch cells, you can cool them like Hyundai or Chevy does with liquid cooling plates and a heat exchanger. If you choose cheaper cylindrical cells, you can use an extrusion with coolant.

I'm keen to know if the Taycan uses direct refrigerant or coolant in its pack. Former is complicated and expensive, but arguably more effective as it drives a much higher delta T.

jonescg said:

I'm keen to know if the Taycan uses direct refrigerant or coolant in its pack. Former is complicated and expensive, but arguably more effective as it drives a much higher delta T.

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Do you mean are the cells immersed in coolant ?.....( as used in Formula E packs),..
..or are they simply in contact with cooling plates ( like the Volt)

..Indicators are it is the latter..
From that report..

The waterproof housing is a sandwich construction consisting of a cover at the top and a bulkhead plate at the bottom. The truss-design battery frame with multiple subdivisions is mounted in between. The cooling elements are glued on underneath the bulkhead plate. The battery housing is secured by means of a steel protective plate. For the battery frame, the developers opted for a lightweight aluminium design.

Click to expand...

jonescg said:

Based on my experience and research on battery thermal management, Tesla has done a very good job with the system they are working with, but it is by no means the best. It has been optimised for the task (driving a 2 ton saloon car down the road a long way) and it does that very well.

But more superior cooling means more complications, more weight, less room for energy storage and so on. If you choose more expensive pouch cells, you can cool them like Hyundai or Chevy does with liquid cooling plates and a heat exchanger. If you choose cheaper cylindrical cells, you can use an extrusion with coolant.

I'm keen to know if the Taycan uses direct refrigerant or coolant in its pack. Former is complicated and expensive, but arguably more effective as it drives a much higher delta T.

Click to expand...

Absolutely agree on all counts, all I was saying with emphasis is that the Tesla topology is superior to indirect cooling plate contact with effectively 1 cell per module. The Volt/Hyundai layout is awesome for power output, but significantly worse in volumetric energy density which is obviously the focus in a long range luxury vehicle. Having a higher delta T cooling loop could make cell temperature variation worse which might have some long term longevity considerations?

For everyone that was anticipating German engineering dominance to smash the upstart Tesla, Taycan is a big disappointment - however measured on its own merits without comparisons it's very impressive for a first attempt.

Not sure on the provenance of this figure, but 800V system is supposed to save 4kg

https://www.caradvice.com.au/789624/porsche-taycan-battery/

I'm not sure if this factors in the 50kW 400-800v dc-dc converter required to allow the car to charge from a standard 400V charger or it's just the difference in cable weight. I imagine the optional 150kW dc-dc conveter is quite a lump.

I think Porsche is expecting 800V to become the standard for fast charging and they'll have a USP or at least a head start over their competition.