[updated with *] P85D 691HP should have an asterisk * next to it.. "Up to 691HP"

[sorka]

Hmmm... maybe I'm wrong. I really think I've seen this... but...

Tesla Model S P85D Insane vs Sport Mode Testing 0 60 MPH in 3 17 Seconds - YouTube

Also tends to support 480kW. And he had separate G gauge showing 3.2 seconds. (Appears upper right, several seconds after the run).



As soon as my car is back together I'll measure (video or some other accurate means). Will be a day or so. Car is currently in pieces for some accessory work I'm co-developing with Artsci.

In both cases, the KW peak hit the same spot on the meter (just below 480) but in the second run, it took a lot longer to get there.

On the first run insane mode, the draw peaks at 40 MPH.
In the second run, it peaks at around 55 MPH.


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Yes, it could be traction. Tires had some abuse lately and 7C was not ideal. I found my vbox today and couldn't get less than 4,1s 0-100 in near ISA contiditions. That's why I prefer 100-200 and 0-200 measurements. Traction becomes insignificant.

It IS traction. Your second video shows the traction light coming on which only shows after traction control has ALREADY been activated. The light only shows after a certain threshold is seen. i.e. traction control can be limiting your 0-60 even if you don't see the light but it goes beyond a certain point, the light will show. It's likely your first video also had traction control but was just under the threshold for the light to show.

 

[mnx]

Agreed. If you want to race, get a race car.
But some people expecting 691hp, GT-R beating performance may be disappointed after spending $100K. I think the OP was.
This car goes like a 200hp econo-box if you push it.

a 4600lb 200hp econo box!

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The Certificate of Conformity of P85+ states "Maximum continuous rated power: 69kW". Wouldn't make a good advertising slogan ;-)

That explains why it limits power so quickly at the track... I definitely look forward to the day when continuous rated power is much larger fraction of peak power.

 

[kirkp]

That's three of us confirming 480kW. I have three different videos all maxxing out about the same spot.

Also, it turns out that the dragstrip has a 220 outlet at the tower they will let me use, so I might be able to get closer to full and also be able to cut the range a bit closer to zero.

If possible you should charge all the way to 100% at your home and the Supercharger (and maybe even at the track). The 20 mile drive from your house or the Supercharger to the track should be enough to bring the battery up to operating temperature even if the outside temps are in the 40's, and a full 100% charge doesn't hurt anything as long as you start burning it off fairly quickly. A 20 mile drive should take you down from 100% to 90-95%. Even a few hours at 100% won't hurt anything, though I wouldn't keep it at that level for any longer than a few hours. In my experience, each 1/8 to 1/4 mile run burns off about 3-5 miles of range.

I charged to 100% each time I took my P85 to the drags every Friday night last summer, and that was about a 25 mile drive to the track for me. I started with a 255 mile rated range when leaving my house and had 237 miles rated when lined up for my first practice run after driving (at very moderate speeds) to the track.

 

[sorka]

Do we know that heating the battery up drastically for 1/4 runs when the battery is near 100% won't hurt the battery? My understanding is that being full and having the battery hot is the real killer. If I ever charge up to 100%, I don't think I'll be doing a lot of stop and go insane driving until it drops to 90%.

 

[loco]

Keep in mind the display is logarithmic, not linear.

OK, then it's 363kW, not 384. I'm seeing 3/5 between 240 and 480. Anyone can take clear a picture/video with more?

 

[krisg81]

In both cases, the KW peak hit the same spot on the meter (just below 480) but in the second run, it took a lot longer to get there.

On the first run insane mode, the draw peaks at 40 MPH.
In the second run, it peaks at around 55 MPH.

I think you are on to something here! I was going to post something today on this after paying attention to it more yesterday and today while driving the car.

It seems when having a full charge, the time to achieve full output, right under 480kW, occurs very quickly and results in very quick/snappy acceleration obviously from a stop, but also already at a cruise punching it from 30MPH on.

As the SOC drops, the time it takes to ramp up to full power is increasing, and that orange power meter is noticeably slower to that ~480kW mark. I haven't timed this, but from what you have already noticed- there is definitely a difference. The feeling of acceleration definitely changes and the car feels less powerful due to the power output being reduced based on battery SOC. This could be attributing to the big drop in performance I am feeling, and it may be why my P85 felt faster and was less affected based on SOC. Maybe the P85 doesn't suffer from this because its a single motor configuration. Perhaps the dual motors draw on a single battery pack has a greater negative affect as the charge levels diminish.

As the SOC drops from 50% - 40% - 30% - etc. the ramping up to that ~480kW level seems to progressively slow. Almost like feathering/modulating the accelerator pedal instead of a stabbing/neck jolting rush that occurs during a full charge.

At launch its less apparent because you are at a stop and AWD traction is still able to give a solid launch- but it is still noticeable after that 30MPH mark that the car is definitely much slower than the Insane mode at higher SOC's.

 

[LetsGoFast]

If possible you should charge all the way to 100% at your home and the Supercharger (and maybe even at the track). The 20 mile drive from your house or the Supercharger to the track should be enough to bring the battery up to operating temperature even if the outside temps are in the 40's, and a full 100% charge doesn't hurt anything as long as you start burning it off fairly quickly. A 20 mile drive should take you down from 100% to 90-95%. Even a few hours at 100% won't hurt anything, though I wouldn't keep it at that level for any longer than a few hours. In my experience, each 1/8 to 1/4 mile run burns off about 3-5 miles of range.

I charged to 100% each time I took my P85 to the drags every Friday night last summer, and that was about a 25 mile drive to the track for me. I started with a 255 mile rated range when leaving my house and had 237 miles rated when lined up for my first practice run after driving (at very moderate speeds) to the track.

My bigger problem this particular weekend may be trying to get the discharging done that I need to get a good range of results. We're hosting a party Saturday night, so I don't have but so much time I can devote to this project Saturday and getting rid of charge will take a while, even at brisk highway speeds. I also need to allocate enough time to supercharge from near empty to near full without being gone from home so long that my wife disowns me. I'm thinking I could pretty easily arrive at something like 30% SOC, do a few runs, knock it down to 15-20%, do a couple more and then make it the 20-odd miles to the Supercharger comfortably. When I return I could probably squeeze in two more, so maybe something like 90% and 75%. If I charge to 100% at the Supercharger, I'll still eat 10% or so driving back to the dragstrip.

Perhaps I'm not thinking this through properly. Maybe it would be more time efficient to show up full and just burn off battery instead of doing the 40 minute round trip to the supercharger + a full charge. I'll need to crunch some numbers.

 

[krisg81]

My bigger problem this particular weekend may be trying to get the discharging done that I need to get a good range of results. We're hosting a party Saturday night, so I don't have but so much time I can devote to this project Saturday and getting rid of charge will take a while, even at brisk highway speeds. I also need to allocate enough time to supercharge from near empty to near full without being gone from home so long that my wife disowns me. I'm thinking I could pretty easily arrive at something like 30% SOC, do a few runs, knock it down to 15-20%, do a couple more and then make it the 20-odd miles to the Supercharger comfortably. When I return I could probably squeeze in two more, so maybe something like 90% and 75%. If I charge to 100% at the Supercharger, I'll still eat 10% or so driving back to the dragstrip.

Perhaps I'm not thinking this through properly. Maybe it would be more time efficient to show up full and just burn off battery instead of doing the 40 minute round trip to the supercharger + a full charge. I'll need to crunch some numbers.

I say show up with as closest to 90-100% as possible and crank out some runs. Leave and drive around a bit, get lunch, whatever and come back with 50% and below and just track data on the way down to 20% SOC- obviously leaving enough juice to go back home

 

[sorka]

I think you are on to something here! I was going to post something today on this after paying attention to it more yesterday and today while driving the car.

It seems when having a full charge, the time to achieve full output, right under 480kW, occurs very quickly and results in very quick/snappy acceleration obviously from a stop, but also already at a cruise punching it from 30MPH on.

As the SOC drops, the time it takes to ramp up to full power is increasing, and that orange power meter is noticeably slower to that ~480kW mark. I haven't timed this, but from what you have already noticed- there is definitely a difference. The feeling of acceleration definitely changes and the car feels less powerful due to the power output being reduced based on battery SOC. This could be attributing to the big drop in performance I am feeling, and it may be why my P85 felt faster and was less affected based on SOC. Maybe the P85 doesn't suffer from this because its a single motor configuration. Perhaps the dual motors draw on a single battery pack has a greater negative affect as the charge levels diminish.

As the SOC drops from 50% - 40% - 30% - etc. the ramping up to that ~480kW level seems to progressively slow. Almost like feathering/modulating the accelerator pedal instead of a stabbing/neck jolting rush that occurs during a full charge.

At launch its less apparent because you are at a stop and AWD traction is still able to give a solid launch- but it is still noticeable after that 30MPH mark that the car is definitely much slower than the Insane mode at higher SOC's.

Except in the case of the video, the difference was due to insane vs sport, not because of SOC.

 

[krisg81]

Except in the case of the video, the difference was due to insane vs sport, not because of SOC.

That makes sense- maybe the same way Sport vs. Insane mode limits the power, this effect automatically occurs as the battery depletes.

This brings me back to thinking Tesla should be more transparent advertising power output and how it is shown transparently to the driver.. i.e. Disable/Grey out the Insane mode once it can no longer run in that mode and performs more like Sport mode because of SOC. As it stands, the car feels slower than Sport mode then the battery starts to get low, yet the car stays on the Insane setting.

 

[sorka]

Yea, if there's an SOC connection that's normal and *NOT* because of a defect in the battery / drive system, what I would expect to see as SOC goes down is less peak KW rather than the same peak but longer to get there.

 

[krisg81]

Yea, if there's an SOC connection that's normal and *NOT* because of a defect in the battery / drive system, what I would expect to see as SOC goes down is less peak KW rather than the same peak but longer to get there.

I am starting to wonder if Elon's tweet regarding an inverter firmware update addresses this very issue that is known, but not publicly stated by Tesla.

 

[sorka]

I have been wondering and suspecting this and even called it on in the my tesla forum last week.

 

[AmpedRealtor]

Hey Amped!

This discussion has really nothing to do with the P85D being a track vehicle, for which it is not and not why someone would purchase it, or expect it to be anything close to a track car.

This is about the car performing with the amount of horsepower it is advertised at, which it does not based on the amount of battery charge. Kind of like your iPhone running fast on a full charge, but slows down tremendously at 50% and lower battery levels.

come on. That's not a fair statement. There are some references to track but really that's just where the observations are being made. Don't let that detract from the point which is that insane mode is short lived and the reference to HP is highly suspect. No one has claimed it to be a track car, nor has anyone even been negative about the car itself. Really if I had to summarize this thread its about a quest for the truth in the claims around insane mode, HP, and the general performance expectations one would expect from the claims.

Thanks guys (or gals), I didn't mean to be controversial. I thought there were two parallel discussions going on. One is regarding Tesla's claim of 691 HP, the other regarding the car not being able to go to a track without power limiting in a short time. I was responding to the latter, but you are totally right in that the Model S should be advertised correctly. I was a little peeved last year when I read reports of the S60 not achieving its HP rating. At the time, some owners were saying that Tesla's spec listed the theoretical motor output, not the actual output. My jaw dropped to the floor! When a vehicle manufacturer advertises a certain Horsepower rating for a vehicle, then the presumption is that the car can, under specified conditions, output the advertised Horsepower.

I would consider Tesla advertising theoretical motor output and not the actual motor output as being somewhat misleading. Telling owners that Tesla qualifies its spec by saying "motor output" is a joke. Every media outlet now reports the P85D's power as being 691 HP. We shouldn't have to resort to word-parsing and reading fine print to figure out what Tesla is really trying to say.

 

[krisg81]

Thanks guys (or gals), I didn't mean to be controversial. I thought there were two parallel discussions going on. One is regarding Tesla's claim of 691 HP, the other regarding the car not being able to go to a track without power limiting in a short time. I was responding to the latter, but you are totally right in that the Model S should be advertised correctly. I was a little peeved last year when I read reports of the S60 not achieving its HP rating. At the time, some owners were saying that Tesla's spec listed the theoretical motor output, not the actual output. My jaw dropped to the floor! When a vehicle manufacturer advertises a certain Horsepower rating for a vehicle, then the presumption is that the car can, under whatever conditions, output the advertised Horsepower.

I would consider Tesla advertising theoretical motor output and not the actual motor output as being misleading. Wow.

Agreed Amped.

I really wonder if there was a 3rd party governing body of Horsepower claims in the EV world if Tesla would truly be able to advertise the P85D (and of course other models of the MS) at 691HP. This is why the SAE must certify true motor horsepower in ICE vehicles before manufacturers can advertise rated engine HP. Because EV's are so new, we only have Tesla's claims to go off of here.

When it comes down to it, especially with performance models of EV's being sold by companies like Tesla, there really needs to be an SAE type certification process. I am going to go out there and say the advertised horsepower of an EV should not be what it sees as peak/ideal horsepower on a full charge- but what its average horsepower output is across the entire spectrum of SOC points are. Like calculate total motor HP output at 100/90/80/70/etc SOC intervals and then thats how its certified. Any environmental factors that vary real-world performance like heat, elevation, traction, cold, etc etc. doesn't matter just like an ICE car. Just some type of certification process like an ICE to make sure Tesla isn't fluffing things to build hype for marketing reasons, which coincidentally is what Elon likes to do with his Twitter account.

 

[kirkp]

My bigger problem this particular weekend may be trying to get the discharging done that I need to get a good range of results. We're hosting a party Saturday night, so I don't have but so much time I can devote to this project Saturday and getting rid of charge will take a while, even at brisk highway speeds. I also need to allocate enough time to supercharge from near empty to near full without being gone from home so long that my wife disowns me. I'm thinking I could pretty easily arrive at something like 30% SOC, do a few runs, knock it down to 15-20%, do a couple more and then make it the 20-odd miles to the Supercharger comfortably. When I return I could probably squeeze in two more, so maybe something like 90% and 75%. If I charge to 100% at the Supercharger, I'll still eat 10% or so driving back to the dragstrip.

Perhaps I'm not thinking this through properly. Maybe it would be more time efficient to show up full and just burn off battery instead of doing the 40 minute round trip to the supercharger + a full charge. I'll need to crunch some numbers.

I think that your last idea is the simplest and easiest.

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Do we know that heating the battery up drastically for 1/4 runs when the battery is near 100% won't hurt the battery? My understanding is that being full and having the battery hot is the real killer. If I ever charge up to 100%, I don't think I'll be doing a lot of stop and go insane driving until it drops to 90%.

I don't think that any of us know this with 100% certainty, but I'm personally very confident that Tesla's Battery Management System is designed to take these worst-case conditions into account. I wouldn't (and haven't) hesitated to do it with my own car, but of course, how you treat your own car is completely up to you.

I also don't think that a single 1/4 mile run is nearly enough to heat up the battery significantly, and then you typically have several minutes until your next run. It's sustained full-power on a track for minutes at a time continuously that really heats up the battery, and even then I think that the motor heating may be the limiting factor over the battery (though again, I'm not sure anyone outside of Tesla knows whether the battery vs. the motor reaches the safety limit first).

When I've run at a timed track, my first run is ALWAYS the fastest, with each subsequent run about 0.1 second slower. When I've done back-to-back runs, they were 7 minutes apart (that's how long it takes me to start the first run, circle back around, stop at the timing booth to pick up my timeslip, and then get back to the ine and begin another run). I attribute the difference in time completely to the SOC, as the battery should have plenty of time to cool back down in those 6 minutes or so.

 

[EarlyAdopter]

When it comes down to it, especially with performance models of EV's being sold by companies like Tesla, there really needs to be an SAE type certification process. I am going to go out there and say the advertised horsepower of an EV should not be what it sees as peak/ideal horsepower on a full charge- but what its average horsepower output is across the entire spectrum of SOC points are. Like calculate total motor HP output at 100/90/80/70/etc SOC intervals and then thats how its certified. Any environmental factors that vary real-world performance like heat, elevation, traction, cold, etc etc. doesn't matter just like an ICE car. Just some type of certification process like an ICE to make sure Tesla isn't fluffing things to build hype for marketing reasons, which coincidentally is what Elon likes to do with his Twitter account.

Why would you specify this for EVs when no ICE car's HP is rated this way? ICE's are rated at peak HP under ideal fuel and atmospheric conditions.

Futhermore, an ICE car's HP rating is at the crank, not at the wheels. Gearing and drivetrain losses on any ICE car reduces real HP to the wheels by 20%.

Likewise, try running an ICE car on a dyno over and over again and watch what happens to peak HP as the engine gets heat soaked. Now try that without any large fans blowing over the front of the car.

 

[krisg81]

Why would you specify this for EVs when no ICE car's HP is rated this way? ICE's are rated at peak HP under ideal fuel and atmospheric conditions.

Because an ICE actually puts down peak horsepower, and is advertised as that power on an engine dyno putting out that peak HP. No where is Tesla stating that advertised HP is certified on an engine dyno. In fact, all we have seen is a P85D on an AWD dyno that put down about 420HP to the wheels, peak, which would be an almost 40%(!) drivetrain loss from advertised peak HP numbers of 691.

Also, ICE peak HP is not dictated by how much fuel in its gas tank is available, whereas it seems the horsepower output of an EV (specifically the Model S' motors) is dictated by its State of Charge in the battery pack. Furthermore, the peak HP rating of an ICE can consistently output that power over and over again as long as fuel is available to it, not how much fuel is in the tank- unlike the motors in the Tesla.

Futhermore, an ICE car's HP rating is at the crank, not at the wheels. Gearing and drivetrain losses on any ICE car reduces real HP to the wheels by 20%.

This is the case with any vehicle, and is really irrelevant here. I am just saying that certifying the horsepower of an ICE or EV motor should be done at the motor on an engine dyno like how they SAE certify it. But unlike an ICE motor, power output is dictated upon its power source- in this case, an 85kW battery where the size of the fuel tank and what fuel levels are in it have no effect on horsepower of an ICE motor.

Likewise, try running an ICE car on a dyno over and over again and watch what happens to peak HP as the engine gets heat soaked. Now try that without any large fans blowing over the front of the car.

Once again, that does not matter. How can we compare parasitic losses of an ICE motor that is based on heat vs an EV motor that loses power by the depletion of energy in a battery pack? Apples and oranges.

 

[sorka]

Because an ICE actually puts down peak horsepower, and is advertised as that power on an engine dyno putting out that peak HP. No where is Tesla stating that advertised HP is certified on an engine dyno. In fact, all we have seen is a P85D on an AWD dyno that put down about 420HP to the wheels, peak, which would be an almost 40%(!) drivetrain loss from advertised peak HP numbers of 691.

Nope, that was only on the rear wheels. The Mustang dyno only works correctly measuring total of front and rear combined *if* powered by a single source. You need a AWD Dynojet to measure a Tesla accurately.

Further more, that particular test, once they were able to keep the wheels from slipping on the dyno which is pretty much unheard of, measured 864 lbs at the rear wheels.....far more than what Tesla claims.

 

[Uncle Paul]

No vehicles advertise a horsepower level that is available at all speeds.

For gas engines the HP and Torque at Zero RPM is Zero. It builds horsepower as it's revs rise. Maximum HP is only available at one specific RPM. At all other RPM's it has a lesser HP.

Expecting an electric motor to produce maximum HP and Torque at all RPM's is foolish.

Electric motors usually produce maximum torque at Zero RPM. At a certain RPM the Torque will fall off. They have different personalities than gas engines.

This is one reason that, while using only one gear, the Tesla walks most gas engines off the line, and that some gas engines have higher top speeds.

If Tesla were to build a racing car, I would suspect that they would provide additional gear ratios.

Tesla's are not designed to be road racing cars. They do very well for short distances, but the high performance drains their batteries quickly.

I have seen custom electric powered cars dominate gas powered street cars at the 1/4 miles. They are designed to shine in this situation, but would not be functional as commuter cars.