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

[sorka]

To gear heads and performance enthusiasts, your data is proving exactly what I have been saying. You have a .5 second variance in the 1/4 and your trap speeds indication a decent amount of horsepower loss. .5 seconds in the 1/4 mile is a big difference in performance- not to the regular crowd, but performance enthusiasts most definitely. The crazy thing is the big drop from 45% SOC to 40% SOC. As I mentioned earlier several times, below 50% SOC is where you *notice* the difference, but it rapidly falls off a cliff from there, making Insane mode feel like Sport mode.

Under 40% is where it just spirals downhill. Lets see data below 40% and go from there. I will be taking my P85D to the drag strip this coming Saturday and I am hoping to have timeslips showing my data as well.

The point of this whole thread is the P85D is much more sensitive to SOC levels than the P85, and its disappointing that performance diminishes so much below half the battery charge. I can understand 20%, but 50% and 40% sucks. At 25% and below its slower than a P85 at the same charge levels, at least what it feels like to me. This is why I believe Tesla needs to address being transparent with their HP rating. With 40% battery and below, the car is clearly losing 75-100HP+ which I don't think is fair to not mention this to consumers.

Actually, trap speed is the indicator of hp, not trap time and there's only 1 mph difference from the highest SOC to the lowest. ET can be effected by many other things other than power but not trap speed.

 

[LetsGoFast]

I'm using his 45% SOC number as the 40% run seems a bit suspect. IE: Slower time, but higher trap speed? The 89 and 45% numbers don't have that anomaly. But even with that... the 1/4 Mile time is 4% different and 1/4 MI speed is 1% different.

I would discount the 60' ft times as that can be a traction issue... specially since the 1/4 mile time is far divergent. I think more runs (data) would bring clarity here.

FWIW, Runs 1,3 and 4 were in Lane 1 and Runs 2&5 were in Lane 2. It is possible that one lane is stickier than the other. I'm going to try to make it to the track Friday night to do a run at lower SOC. If I can work it out, I'll post those numbers as well. I also strongly suspect that the heat soak was a much bigger factor for Run 5 than the SOC, but we need more data before we can draw any firm conclusions.

I also think that it may be possible that the strong winds could have had an effect. On the videos of the later runs, you can hear the wind noise very loudly. Hopefully I'll get to do another test without the wind. I'm not sure how much effect it could have, but 1 or 2% wouldn't shock me.

 

[fiksegts]

run in the same lane for sure when comparing, our track has a few MPH difference between the two lanes.....

FWIW, Runs 1,3 and 4 were in Lane 1 and Runs 2&5 were in Lane 2. It is possible that one lane is stickier than the other. I'm going to try to make it to the track Friday night to do a run at lower SOC. If I can work it out, I'll post those numbers as well. I also strongly suspect that the heat soak was a much bigger factor for Run 5 than the SOC, but we need more data before we can draw any firm conclusions.

I also think that it may be possible that the strong winds could have had an effect. On the videos of the later runs, you can hear the wind noise very loudly. Hopefully I'll get to do another test without the wind. I'm not sure how much effect it could have, but 1 or 2% wouldn't shock me.

 

[LetsGoFast]

run in the same lane for sure when comparing, our track has a few MPH difference between the two lanes.....

I was trying to be a nice guy and let friends run against each other. I would have preferred to be in the same lane every time. Runs 1 and 3 were the ones I thought were the key comparisons. I wouldn't have expected it to make that much difference, but maybe it did.

 

[Danal]

More data: I did a run at 88% and at 49%. Video of dash. Maybe lag, but should be consistent lag.

I gotta tell you, at 30 Frames per Second, the difference between the two is 113 frames vs. 117 frames. In one way, that is 3.63%. However, given that I could be counting +/- 1 at either the start or the 60 point, and similar, it would also be fair to say it could be two frames, which approaches being statistically insignificant.

Need a lot more data... but... based on letsgofast track timeslips and my videos, the difference in the 90% area and 50% area doesn't seem very big. I'm sure it will fall of a cliff somewhere... 20%? 10%? Don't know, but somewhere...


Anyway, NEED MORE DATA. Please video runs! Place rows here (it is openly editable): P85D Accel Data Capture

 

[krisg81]

Danal, thanks for that man ! I'll tell you, the difference at 49% isn't huge and is only slightly noticeable. That's just where I notice tapering/loss of HP beginning. The real fall off is below 40%. 30-20% is drastic IMO, where there has to be around a 100HP loss. I've seen data with runs in the 40-50% area, but that charge level isn't very significant of a drop off. The 20-30% area seems to have a much larger % drop of power versus a single motor P85 at the same SOC levels which is my point. I'd say it's less power than Sport mode and higher SOC levels.

 

[Danal]

Danal, thanks for that man ! I'll tell you, the difference at 49% isn't huge and is only slightly noticeable. That's just where I notice tapering/loss of HP beginning. The real fall off is below 40%. 30-20% is drastic IMO, where there has to be around a 100HP loss. I've seen data with runs in the 40-50% area, but that charge level isn't very significant of a drop off. The 20-30% area seems to have a much larger % drop of power versus a single motor P85 at the same SOC levels which is my point. I'd say it's less power than Sport mode and higher SOC levels.

Cool! We'll keep getting runs. I'm charging at the moment... relatives in town and I want to punch the car at 90% or more . Within the next day or two, I will let it run down and keep videoing as it does.

 

[sorka]

Danal, thanks for that man ! I'll tell you, the difference at 49% isn't huge and is only slightly noticeable. That's just where I notice tapering/loss of HP beginning. The real fall off is below 40%. 30-20% is drastic IMO, where there has to be around a 100HP loss. I've seen data with runs in the 40-50% area, but that charge level isn't very significant of a drop off. The 20-30% area seems to have a much larger % drop of power versus a single motor P85 at the same SOC levels which is my point. I'd say it's less power than Sport mode and higher SOC levels.

And given we don't have any real data below 40%, it could be that your falloff is what happens to everyone. We just don't have any proof yet. I have my P85D now, but it's sitting at home 130 miles away. I had to take the train to pickup my Prius at work an won't be home for a few days. Even then, my MS is at an 80% charge right now. I realize the reality of collecting this type of data could be quite a bit of effort if you want to do it in similar conditions without waiting days in between different states of charge.

 

[LetsGoFast]

Danal, thanks for that man ! I'll tell you, the difference at 49% isn't huge and is only slightly noticeable. That's just where I notice tapering/loss of HP beginning. The real fall off is below 40%. 30-20% is drastic IMO, where there has to be around a 100HP loss. I've seen data with runs in the 40-50% area, but that charge level isn't very significant of a drop off. The 20-30% area seems to have a much larger % drop of power versus a single motor P85 at the same SOC levels which is my point. I'd say it's less power than Sport mode and higher SOC levels.

I can't just let this go. Your new position is a significant change from your original claims:

That is also the issue. I love everything about it. That is, until the battery drops below 50%. The power is noticeably reduced. Not by a little, but to where I notice the Insane mode is no longer insane- but rather reduced to what feels like the Sport mode when the SOC is lower. It may even happen sooner than 50%.
. . .
When it is below 50% battery, I swear.. it feels slower than my P85 did at almost any charge level.. yes, slower.

 

[krisg81]

I can't just let this go. Your new position is a significant change from your original claims:

I have had more time with the car since the original post- I am noticing differences. I started this thread when I had the car less than a week. Its not so noticeable at 50%, its slightly under that it starts feeling like its in perma-Sport mode than feels slower/less peppy than my previous P85. Below 30% is a huge difference, where it has to be around a 100HP+ loss or so, but of course no data to back it up- but its a big difference to me.

 

[EarlyAdopter]

I have had more time with the car since the original post- I am noticing differences. I started this thread when I had the car less than a week. Its not so noticeable at 50%, its slightly under that it starts feeling like its in perma-Sport mode than feels slower/less peppy than my previous P85. Below 30% is a huge difference, where it has to be around a 100HP+ loss or so, but of course no data to back it up- but its a big difference to me.

On a car that you charge to 90% every night, if this is something that only comes into play below 30% why are we spending so much time on this?

I mean, how often is someone going to drive 150+ miles in a day and then come along and say "Ok, now I need max acceleration!"?

 

[LetsGoFast]

I have had more time with the car since the original post- I am noticing differences. I started this thread when I had the car less than a week. Its not so noticeable at 50%, its slightly under that it starts feeling like its in perma-Sport mode than feels slower/less peppy than my previous P85. Below 30% is a huge difference, where it has to be around a 100HP+ loss or so, but of course no data to back it up- but its a big difference to me.

The P85 also got noticeably slower at 20% too, right? I know that I've seen a Bjorn video where he talks about that (or maybe a news from the frunk one).

 

[Danal]

This is interesting:

[video]http://m.autoevolution.com/2015-tesla-model-s-p85d-hits-the-dyno-trolls-us-with-864-lb-ft-of-torque-video-90473.html[/video]

Tesla Model S P85D Shocks the Dyno with 864 ft-lbs of Torque | DragTimes.com Drag Racing, Fast Cars, Muscle Cars Blog

The comments raise more questions than they answer into the context of this thread... And, it is crystal clear that they never got a run that captures on the Dyno the way we launch the car on the street: Stomp the go pedal. They had to ease the pedal down to get past tire slip. This is the Drag Times session that produced the curve that we analyzed earlier in this thread. So... that curve pretty much inaccurate. Bummer.

Still don't know where the HP numbers are claimed, Shaft? Input? etc, etc.

 

[mnx]

On a car that you charge to 90% every night, if this is something that only comes into play below 30% why are we spending so much time on this?

I mean, how often is someone going to drive 150+ miles in a day and then come along and say "Ok, now I need max acceleration!"?

Exactly, the solution to krisg81's problem is simple. Charge you damn car. *end of thread*

 

[krisg81]

Exactly, the solution to krisg81's problem is simple. Charge you damn car. *end of thread*

There was never a problem that I need solved. Once again... I was simply making a point Tesla needs to be transparent on advertised horsepower as the rated 691HP output obviously diminishes based on SOC levels, and falls off a cliff past half full. I still don't understand why people don't get this- it's like arguing with an Apple fanboy. When the car loses at least 100HP at 30% SOC and below, how is this ok for a company to market this power is available all the time? Let's not forget it's clear this 691HP is only available under 50MPH, and after that it performs very close to their 417HP P85, and 380HP S85/60 cars. Hence, needing an asterisk when marketing this horsepower, because it sure as hell doesn't perform like a 691 horsepower car all the time.

 

[fiksegts]

updated my P85D to 6.2, no speed or acceleration increases.... disappointing since it was said to be in this release...

same exact times as a few weeks ago, 11.6 @ 115.x MPH with 0-60 in 3.1 and 0-100 in 8.3....

 

[mnx]

There was never a problem that I need solved. Once again... I was simply making a point Tesla needs to be transparent on advertised horsepower as the rated 691HP output obviously diminishes based on SOC levels, and falls off a cliff past half full. I still don't understand why people don't get this- it's like arguing with an Apple fanboy. When the car loses at least 100HP at 30% SOC and below, how is this ok for a company to market this power is available all the time? Let's not forget it's clear this 691HP is only available under 50MPH, and after that it performs very close to their 417HP P85, and 380HP S85/60 cars. Hence, needing an asterisk when marketing this horsepower, because it sure as hell doesn't perform like a 691 horsepower car all the time.

The 50mph issue you mention is related solely to the lack of a multi speed transmission. This is no different from any car with an ICE and has been mentioned several times.

IMO the bigger issue is the motor being rated for 69kW continuous. Not many people track their Tesla's but for those that do, it's not fun to have the power cut in half! That's far worse than the 100hp? reduction you are feeling.

 

[sorka]

There was never a problem that I need solved. Once again... I was simply making a point Tesla needs to be transparent on advertised horsepower as the rated 691HP output obviously diminishes based on SOC levels, and falls off a cliff past half full. I still don't understand why people don't get this- it's like arguing with an Apple fanboy. When the car loses at least 100HP at 30% SOC and below, how is this ok for a company to market this power is available all the time? Let's not forget it's clear this 691HP is only available under 50MPH, and after that it performs very close to their 417HP P85, and 380HP S85/60 cars. Hence, needing an asterisk when marketing this horsepower, because it sure as hell doesn't perform like a 691 horsepower car all the time.

I'm in total agreement that Tesla should be transparent about this. However, I don't believe the P85D is ever making the claimed hp. There's not a single dyno to prove that it does and the one piece of evidence we do have says it's not even close.

The KW meter never reaches 480 KW let alone 515 KW. In fact because the meter is logarithmic, it may only be reaching 400 KW or so. The only explanation if this wasn't accurate is if it didn't include the draw for the front motor but I doubt that's the case.

However, I don't agree that the power is being reduced in normal cases.

Even this video, where the driver goes up to 100 MPH in insane mode, the KW meter never backs off even up to 100 MPH.

Tesla Model S P85D - 0 to 104 MPH Launch - YouTube

It peaks around 30 MPH and stays there all the way through 100+. It's only got 160 miles rated charge(63%) so it's not like they did this in ideal conditions.

The P85D does the 1/4 about a second faster than other cars that have the same trap speed. If it wasn't for it's sudden massive torque available right at launch, it would be a 12.5 second car so there's not way it's ever making 691 hp even at 2.5 tons.

No dynos yet from an actual Dynojet. The one dyno we do have is from a Mustang dyno and those are notoriously inaccurate. I dynoed a 300zx twin turbo with larger turbos, injectors, intercoolers, intake, exhaust running 1.2 bar. g-tech was giving me 0-60 runs in 4 seconds flat. Mustang dyno said I was making 240 rwhp. Dynojet the same day with the same boost gave me 406 rwhp.

 

[bp1000]

I'm confused as it seems hard to grasp.

A 700bhp tesla lines up next to a 700bhp lambo. Tesla beats lambo off line, lambo over takes tesla after 7 seconds or around 85-90mph. Lambo continues to pull away as it has a gearbox.

Lambo reaches peak power almost at max RPM in each gear. The better the launch the earlier the lambo will start to pull away.

Tesla is setup for max power very early on and reduces power as it gets faster (no gears). Opposite of the lambo which can stay in power band until 6th gear. One could argue tesla is more usable due to max power within legal speed limits.

Tesla is up to 691bhp just like the lambo is up to 700bhp depending on RPM. Lambo may also provide variable results on a dyno especially on a RWD only dyno! Lambo is easier to measure as peak power comes once we are moving. Peak power happens almost immediately in tesla, v.hard to measure.

Back calculating power draw is arriving at conclusions that suggest motors are not producing 691bhp in tesla, even at peak as the draw is what 480kW. That maybe the case, who knows. Its keeps a 700bhp lambo keen until 80mph, then the lack of gearing starts to show, sooner if the lambo launches well, tesla will nail it to 30mph and win (likely), lambo gets into 2nd gear at around 45mph and power sustained means tesla is going to start seeing the lambo fly past at 65mph if launched well, or 85mph if launched without clutch dump as lambo hits 3rd gear at around 80mph.

 

[Danal]

I do have access to a 4-wheel Dynojet, and a person who will work with me on the challenge of an accurate reading. But... it will be at least a week and a half before I can get there. Maybe more.


Please, somebody beat me to it....