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

[SDRick]

At about 30 MPH we both punched it..... and she smoked me. Not by a little either, by more than a car length. She was driving a P85 with less than 50% SoC and I was driving my P85D with about 85% SoC. It took until about 70 MPH before I started to even gain on her, and even then super slowly. By the time we let off around 80 MPH I hadn't even gotten even with her yet.

We definitely punched it at the same time, too. Clear, dry conditions. ~75F.

Very hard to believe. There must be something wrong with the D. (Perhaps all your cylinders aren't firing)! I drove both, the D was noticeably faster.

 

[Andyw2100]

My big question is very simpel.... Elon and Co said one very interesting thing during the launch.... He said... It has the same performance as the McLaren F1. Now tell me dear freinds. This European car build was it 15 or 20 years ago... Did it do 0-60 mph in 3.2 s or was it with 1 foot roll out so it actually did 4-60 mph.... ?

I asked essentially the same question months ago. When it looked like no one was going to try to answer the question, I went digging for the answer myself. I didn't come up with anything 100% definitive, but the following is what I found:

P85D vs GTR - PerformanceBox data vs drag strip slip data... help? - Page 3

I think this is asking what I asked earlier, and what wk057 said he immediately wondered too, which is, essentially, do the Tesla P85D and McLaren F1 have roughly equivalent 0-60 times, or is there a chance that the P85D time included one-foot rollout while the McLaren F1 time did not, which would make the McLaren F1 .3 seconds, give or take, faster 0-60.

I had hoped someone with more expertise would definitively answer this. But I don't believe anyone has, or if they have I didn't understand it.

I admittedly do not have any expertise in this area, but I did do some searching, and I believe what I found answers the question with a reasonable amount of certainty. The answer is that the cars do have very similar 0-60 times, and that the comparisons were apples to apples. This is what I found.

I started with the Wikipedia article on the McLaren F1, which supports the 3.2 0-60 time: McLaren F1 - Wikipedia, the free encyclopedia

The reference to support that time is an article in "Autocar:" McLaren F1 1992-1998 performance | Autocar

That article doesn't say explicitly whether or not 1-foot rollout was used.

Digging a little more, I found this article, also in "Autocar:" How much do performance figures on sports cars actually matter? | Autocar

In the article immediately above, the author gives several reasons why American magazines often report slightly better 0-60 times than his magazine does. He talks about things like weight, fuel being carried, etc., but never mentions 1-foot rollout as a factor. He would have had to include that, since it is such a big factor, if, in fact, his publication and the American publications were doing things differently. Here's just one paragraph from the article, so you get a feel for it:

"American magazines have a habit of producing unusually rapid figures on cars, after all; always have done, always will do. Call it the unfair advantage, call it what you will, but for a long time it’s been an unwritten rule of road testing that the US mags tend to record faster times on their cars than everyone else."

This article would have had to have mentioned 1-foot rollout as a difference, if there was a difference.

So I think, based on the above, it is reasonably safe to conclude that the times being thrown around for the McLaren F1, like the times being thrown around for the Tesla P85D, do include 1-foot rollout, meaning the comparisons are valid, and the cars have similar 0-60 times.

 

[wk057]

I think the only way to know for sure is to see a drag race between a P85D and a McLaren F1. Know anyone who has one?

- - - Updated - - -

Very hard to believe. There must be something wrong with the D. (Perhaps all your cylinders aren't firing)! I drove both, the D was noticeably faster.

From a 30-40 MPH roll, it just isn't.

- - - Updated - - -

I actually just heard back from a friend who I gave the task of finding a place for testing. He said we may be able to setup camp at a regional airport with a 1.2 mile runway and could likely get 90 minutes to 2 hours of either early morning (~6AM) or late evening time (8PM) to do testing. I'm looking into availability for this and pricing and such, as this would be perfect.

If possible it'd be awesome to get a time setup and get together some other models (S60, 70D, S85, 85D) to show up, but would need to probably gather at my place or something first to top everyone's packs off depending on where people would come from.

 

[thegruf]

Actually thinking about it, maybe not so surprising after all. P85D a fair bit heavier than the P85, so (as we now know) you are both likely current limited maybe the P85 will esge it initially.
Used to have similar issue with RS5 450hp vs S5 350hp - nothing in it until the RS really got into it's stride.

 

[Andyw2100]

I actually just heard back from a friend who I gave the task of finding a place for testing. He said we may be able to setup camp at a regional airport with a 1.2 mile runway and could likely get 90 minutes to 2 hours of either early morning (~6AM) or late evening time (8PM) to do testing. I'm looking into availability for this and pricing and such, as this would be perfect.

If possible it'd be awesome to get a time setup and get together some other models (S60, 70D, S85, 85D) to show up, but would need to probably gather at my place or something first to top everyone's packs off depending on where people would come from.

Knowing what I know about Jason (just from his posts--we've never met) I'm not only fully expecting to see this come off with some amazing video and very controlled comparison testing, but I'm at least half-expecting to see video of some sort of jury-rigged mobile HPWC that he will have hooked up at the airport, to charge cars between runs!

 

[wk057]

Knowing what I know about Jason (just from his posts--we've never met) I'm not only fully expecting to see this come off with some amazing video and very controlled comparison testing, but I'm at least half-expecting to see video of some sort of jury-rigged mobile HPWC that he will have hooked up at the airport, to charge cars between runs!

I was actually thinking about something like that lol.

At the very least there will be many GoPros.

 

[apacheguy]

Can someone point me to the post in this giant mass of a thread where the PD owners calculated 500 HP max?

I get, assuming 100% SOC 400 V * 1300 A = 520 kW = 697 HP. Even with 90% efficiency we are only down to 627, but 500 where does that come from exactly?

Mods : This thread could seriously benefit from a summary after the OP!

 

[stopcrazypp]

Can someone point me to the post in this giant mass of a thread where the PD owners calculated 500 HP max?

I get, assuming 100% SOC 400 V * 1300 A = 520 kW = 697 HP. Even with 90% efficiency we are only down to 627, but 500 where does that come from exactly?

Mods : This thread could seriously benefit from a summary after the OP!

REST says 550 hp. I think the lower power number is from voltage sag at peak power draw, according to others.

 

[sorka]

Can someone point me to the post in this giant mass of a thread where the PD owners calculated 500 HP max?

I get, assuming 100% SOC 400 V * 1300 A = 520 kW = 697 HP. Even with 90% efficiency we are only down to 627, but 500 where does that come from exactly?

Mods : This thread could seriously benefit from a summary after the OP!

REST API 415KW at the battery. 550 hp before losses. Less by the time it hits the motor shaft which is where manufacturers specify horsepower. But not much less.

VBox says just under 500 at the wheels with a REST reading of 415KW so only about a 9.1% drivetrain loss which sort of makes sense that it would be a lot less of a loss than a typical ICE AWD given that ICE AWDs have to go through a multi speed transmission, flywheel, torque converter (for autos), transfer case, and two drive shafts. The Tesla is much more of a direct drive going through a reduction gear and then an open diff.

 

[wk057]

Can someone point me to the post in this giant mass of a thread where the PD owners calculated 500 HP max?

I get, assuming 100% SOC 400 V * 1300 A = 520 kW = 697 HP. Even with 90% efficiency we are only down to 627, but 500 where does that come from exactly?

Mods : This thread could seriously benefit from a summary after the OP!

As explained somewhere up thread you can't just multiply out A*V=kW=HP here. That number is meaningless in the real world and meaningless more so with batteries.

The voltage drop due to internal resistance of the cells at these power levels (1300A) would sag the voltage something like 15-20%. So assuming no losses in wiring, inverter, and motor (impossible) that's still only ~422kW, which is on par with what we're seeing from the REST API.

 

[rns-e]

Can someone point me to the post in this giant mass of a thread where the PD owners calculated 500 HP max?

I get, assuming 100% SOC 400 V * 1300 A = 520 kW = 697 HP. Even with 90% efficiency we are only down to 627, but 500 where does that come from exactly?

Mods : This thread could seriously benefit from a summary after the OP!

Three dyno tests says between 413 and 460 hp

US dyno by Brooks 413: http://www.dragtimes.com/2015-Tesla-Model-S-Dyno-Results-Graphs-27143.html

DK dyno 430: http://teslaforum.dk/ow_userfiles/plugins/base/981-Tesla_Dyno.png

FIN dyno 460:http://www.teslaclub.fi/blog/22/P85D+dyno-testissä/

The way of rest API saying 555 is like calculating the amount of gas going into the engine and converting that number to hp - makes no sense

 

[stopcrazypp]

Three dyno tests says between 413 and 460 hp

US dyno by Brooks 413: http://www.dragtimes.com/2015-Tesla-Model-S-Dyno-Results-Graphs-27143.html

DK dyno 430: http://teslaforum.dk/ow_userfiles/plugins/base/981-Tesla_Dyno.png

FIN dyno 460:http://www.teslaclub.fi/blog/22/P85D+dyno-testissä/

The way of rest API saying 555 is like calculating the amount of gas going into the engine and converting that number to hp - makes no sense

Given the P85 dynoed at 430whp (and at similar SOCs too), I doubt the first two dynos were valid. Even the last one represents a 16% loss, which is higher than expected. What they all failed to do was to track REST numbers at the same time (which would let us know if the car was outputting full power or if TC was killing things).

What sorka got of 500whp (~10% loss) on vbox while tracking REST at 550hp is more believable.

 

[WarpedOne]

Actually thinking about it, maybe not so surprising after all. P85D a fair bit heavier than the P85, so (as we now know) you are both likely current limited maybe the P85 will esge it initially.
Used to have similar issue with RS5 450hp vs S5 350hp - nothing in it until the RS really got into it's stride.

Yup, people just cannot understand they are battery power limited.
One motor, 10 motors, shmotors. Its the same 85 kWh battery that is moving all those pounds around. More pounds, less moving.

 

[wk057]

Yup, people just cannot understand they are battery power limited.
One motor, 10 motors, shmotors. Its the same 85 kWh battery that is moving all those pounds around. More pounds, less moving.

It's not the battery capacity that is limiting the output power, it is software and maybe the main pack fuse (the test curve from the manufacturer says it can handle it for a brief calculated time consistently). I've personally tested the Model S 85 kWh cells at power levels of 6C+ without issue. About 6.5C would be needed to push the kW numbers needed for closer to 691 HP worth of power, and the cells are capable.

The cell level fuses will limit safe output to somewhere around 6.5C, so that's probably the max of the pack configuration. Bigger cell level fuses (ie, same cells in a new pack) could easily do 10C with the liquid cooling setup, which is closer to 900HP possible from the same cells.

(I'm pretty sure I've posted this in response to you and/or others who have previously posted this same uninformed nonsense about it being the batteries, but it definitely is not the case).

 

[rns-e]

Given the P85 dynoed at 430whp (and at similar SOCs too), I doubt the first two dynos were valid. Even the last one represents a 16% loss, which is higher than expected. What they all failed to do was to track REST numbers at the same time (which would let us know if the car was outputting full power or if TC was killing things).

What sorka got of 500whp (~10% loss) on vbox while tracking REST at 550hp is more believable.

Sure - the three independent dyno runs that measures at the drum must be at fault, whereas the one vbox that is doing an estimate must be right. I know the numbers are not what people like to hear, but hey ...

 

[MuppetOwl]

Sure - the three independent dyno runs that measures at the drum must be at fault, whereas the one vbox that is doing an estimate must be right. I know the numbers are not what people like to hear, but hey ...

I have tuned many cars on dynos and know they limitation. Also I have tried to dyno Teslas, its not possible to get correct. The roller dynos don't support 2 engines with different output and Dynapack is not possible to use because of the gear ratio and does not support different gear ratio front and back.

If the 430hp numers is correct, that is the same as P85 as some have dynoed the P85 to. We know for a fact that the P85D is faster also at higher speeds so it must put down more kW. At higher speeds the difference is not very much but it is there. The biggest different is how fast the P85D ramps up the power since it is not as traction limited as P85. Also none of the roller dynos I have tried are able to not slip if you have max power from a standstill, so they are not able to measure power where the P85D have the most.

The HP number for the P85D I think is somewhere around 500-520

 

[rns-e]

I have tuned many cars on dynos and know they limitation. Also I have tried to dyno Teslas, its not possible to get correct. The roller dynos don't support 2 engines with different output and Dynapack is not possible to use because of the gear ratio and does not support different gear ratio front and back.

If the 430hp numers is correct, that is the same as P85 as some have dynoed the P85 to. We know for a fact that the P85D is faster also at higher speeds so it must put down more kW. At higher speeds the difference is not very much but it is there. The biggest different is how fast the P85D ramps up the power since it is not as traction limited as P85. Also none of the roller dynos I have tried are able to not slip if you have max power from a standstill, so they are not able to measure power where the P85D have the most.

Different gearing and two engines means nothing to a dyno, as the drums equals the road and the front and back wheels are doing the same speed when not slipping.

Correct about the standstil, but max hp is not measured from a standstil, that only influenses max torque and the car do not spin the wheels at max hp.

The difference in acceleration between P85D and P85 is down to massively more torque and not hp

EDIT: Also, if your statement about the dynos not supporting two engines with different output is correct, then dynos would not be able to measure any awd cars that do not have 50/50 power distribution between front and back. The two engine build up means nothing to dynos, it is just another way of distributing power than with a diff and shaft.

The only thing difficult for dynos are the instant torque and that is more down to how brave the operator is and making sure the car is tied down correctly - it will fly of the drums with that torque very fast

 

[WarpedOne]

it is software and maybe the main pack fuse

And those software limitations and that fuse are there because tesla cleary doesn't know what they are doing because you have:

I've personally tested the Model S 85 kWh cells at power levels of 6C+ without issue.

One thing is pushing one cell without it exploding, quite different thing is warranting the whole production spec to see 8 years lifetime with X degradation and not more.
A bigger / stronger battery system will enable higher max power output.

You tinkering means nothing, nothing at all.

 

[darthy001]

And those software limitations and that fuse are there because tesla cleary doesn't know what they are doing because you have:



One thing is pushing one cell without it exploding, quite different thing is warranting the whole production spec to see 8 years lifetime with X degradation and not more.
A bigger / stronger battery system will enable higher max power output.

You tinkering means nothing, nothing at all.

Well, according to Tesla all you need is the new ludicrous-upgrade and the 85kwh battery can output much more power. So clearly the 85kwh-cells and the capacity arent the issue.. Or are you saying that Teslas "tinkering" means nothing at all as well?

 

[MuppetOwl]

Different gearing and two engines means nothing to a dyno, as the drums equals the road and the front and back wheels are doing the same speed when not slipping.

Correct about the standstil, but max hp is not measured from a standstil, that only influenses max torque and the car do not spin the wheels at max hp.

The difference in acceleration between P85D and P85 is down to massively more torque and not hp

Yes for drums gearing is not a problem, but for a Dynapack it is. I did explain the problem with the dynapack earlier in this thread.

HP is torque x rpm
Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.


Edit: added my earlier post about Dynapack dyno a rwd Tesla. Dual motor Tesla give another issue if the gearing is not the same, since the dynapack must know what the gearing is to calculate power.

I do some tuning on Subaru's and use a Dynapack DAQ54. I have tried the Tesla and its not possible to get correct hp/nm. I always get a to much torque error and it shuts down to protect itself if I floor it from start. Have to wait to about 50-60 km/h before i can floor it.

The reason is that the Dynapack DAQ54 is rated to 2625hp/8500nm (4wd) and 1390hp/4500nm (2wd) on the hubs. But the gear ratio on the Tesla is the problem. On a normal car we always dyno in the gear that is closest to 1:1 ratio.

For the Tesla the gear ratio is 9.73:1. So the torque for the rear engine is 5838nm on the hubs and the front is 3210nm. So the front engine is no problem, it is the rear that shuts down the dyno because the limit is 4500nm on the rear pods.
The dynapack is also very unhappy with the instant torque the Tesla does make.

I had a Subaru STi before that did make 510hp/667nm. 4th og 5th gear no problem in the dynapack. But if I had tried 1 gear, it will be 9458nm on the hubs. So the dynapack will then shut down and give a to much torque error

To convert NM to lb*ft go here. Im to lazy
Convert lb*ft to N*m - Conversion of Measurement Units