I can't remember when they showed "motor power" for the other models, but I think that was only for a short time? When the P85D first came out, and currently, they're showing the real ratings of all models except P85D.
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
P85D and P90D horsepower disagreement
- Thread starter MuppetOwl
- Start date
-
- Tags
- Driving Dynamics Model S
I can't remember when they showed "motor power" for the other models, but I think that was only for a short time? When the P85D first came out, and currently, they're showing the real ratings of all models except P85D.
stopcrazypp
Well-Known Member
Yes, it was only for a short time, the roughly the same amount of time that the P85D was advertised at 691hp "motor power". When they removed the 691hp number, they also removed all the motor power numbers. Now they have added back the motor power numbers (but also have kept the system power number).
I can put a specific time frame on it. "Motor power" was added to the site with the launch of the "D" models on October 10, 2014:
http://www.greencarreports.com/news...ower-numbers-for-tesla-model-s-whats-the-deal
"Motor power" was still on the site March 30, 2015:
https://web.archive.org/web/20150330020918/http://www.teslamotors.com/models#battery-options
"Motor power" was removed sometime in early April 2015, and numbers reverted back (looks like 691hp for P85D was still there though):
https://web.archive.org/web/20150410112745/http://www.teslamotors.com/models#battery-options
"Motor power" was removed for P85D in mid-May 2015:
https://web.archive.org/web/20150518012003/http://www.teslamotors.com/models#battery-options
http://www.teslamotorsclub.com/show...691HP/page68?p=1007850&viewfull=1#post1007850
Note that I'm talking about the US website above, the European sites seems to have shown "motor power" the entire time (I forgot to mention on the European site the S85D was also advertised at 522hp "motor power").
Last edited:
I just checked the Japanese site, instead of "motor power" it says "motor output". This is clearly untrue because at no point in time do the motors output that much power.
stopcrazypp
Well-Known Member
I think that is just a quirk of the Japanese language. When you say horsepower (hp) it is 馬力 (馬=horse 力=power), when you say kilowatts (kW) you typically use 出力 (出=coming out 力=power). I suppose the "out" there is to distinguish between the power into the motor and out of the motor.
https://ja.wikipedia.org/wiki/馬力
https://www.orientalmotor.co.jp/tech/teruyo/vol21/
Straight translation of モーター出力 is motor output power.
http://www.teslamotors.com/jp/models#battery-options
Last edited:
出力 is really just "output", it doesn't specifically refer to power, even though it contains the character 力. This is because when the word was first imported from Chinese centuries ago it used to mean "to show effort", but some dude decided to use this particular word to translate the English word "output" in 1908, and this is the meaning that remains today.
stopcrazypp
Well-Known Member
Wikipedia says 出力 means "機械の動力の大きさ" (power magnitude of machinery) when used in context.
Thus "motor output power" or even just "motor power" is a better translation than "motor output".
https://translate.google.com/translate?hl=en&sl=ja&tl=en&u=https://ja.wikipedia.org/wiki/出力
jcaspar
Member
Does anyone know how HP is calculated on a dyno with a Tesla? Normally the dyno measures torque and this is multiplied by engine RPM and divided by 5252. What is used for RPM?
The only formula I saw for (electrics is volts x current x efficiency)/746.
The only formula I saw for (electrics is volts x current x efficiency)/746.
stopcrazypp
Well-Known Member
I think some dynos can pick up the rpm from the OBD-II port, but not sure if Tesla provides that.
The mustang dynos (eddy current dynos) do calculate power from torque, but the dynojet (inertia dynos) calculates torque from power.
http://houstonperformancetrucks.com/showthread.php?11200-Mustang-Dyno-vs-Dyno-Jet
http://blog.americanmuscle.com/why-does-my-mustang-put-down-less-hp-than-ford-advertises/
stopcrazypp
Well-Known Member
I posted this in the other forum but no replies relevant to the discussion:
Just trying to figure this out. The current 1300 amp fuse must be run at a 20% margin because heat melting fuses melt at different current levels depending on time i.e. the breaking point is dependent on both time and heat.
80% of 1300 amps * 400 volts = 416KW. The highest API reading ever was 415KW although most report a maximum of 414KW. The specification of max KW is pretty much identical to what is measured at 100% SOC. This is 557 hp at the battery.
OK, so the new fuse is 1500 amps. However, it's not a traditional fuse that melts based on current and time. It uses explosives to blow the connection when an independent monitoring circuit detects that the current level is exceeded. This means the fuse could be run up to exactly 1500 amps. But is this what will actually happen or do people think they'll also use an 20% margin?
If they do use an 20% margin, then it's 80% of 1500 * 400 = 480KW = 643 hp at the battery.
But if this is 1500 amp fuse that doesn't require the 20% margin, then it would be 100% of 1500 * 400 = 600KW = 804 hp at the battery. If we factor in a mere 4% dc-dc conversion loss + the motor conversion (electricity into the motor terminals to the motor shaft) that would lower it to 772 hp by the time it hits the motor shaft.
It will certainly required a lot more than 86 hp (643 - 557) to bring the 1/4 mile from 11.7 down to 10.9 in a 5000 lb car.
Just trying to figure this out. The current 1300 amp fuse must be run at a 20% margin because heat melting fuses melt at different current levels depending on time i.e. the breaking point is dependent on both time and heat.
80% of 1300 amps * 400 volts = 416KW. The highest API reading ever was 415KW although most report a maximum of 414KW. The specification of max KW is pretty much identical to what is measured at 100% SOC. This is 557 hp at the battery.
OK, so the new fuse is 1500 amps. However, it's not a traditional fuse that melts based on current and time. It uses explosives to blow the connection when an independent monitoring circuit detects that the current level is exceeded. This means the fuse could be run up to exactly 1500 amps. But is this what will actually happen or do people think they'll also use an 20% margin?
If they do use an 20% margin, then it's 80% of 1500 * 400 = 480KW = 643 hp at the battery.
But if this is 1500 amp fuse that doesn't require the 20% margin, then it would be 100% of 1500 * 400 = 600KW = 804 hp at the battery. If we factor in a mere 4% dc-dc conversion loss + the motor conversion (electricity into the motor terminals to the motor shaft) that would lower it to 772 hp by the time it hits the motor shaft.
It will certainly required a lot more than 86 hp (643 - 557) to bring the 1/4 mile from 11.7 down to 10.9 in a 5000 lb car.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
Sorka: you're likely on to something here. Seeing as the new fuse is a new type of fuse, let's call it "actively managed", I think comparing ratings (as compared with traditional fuses) is a bit apples to oranges.
So yes, it could be that with the new fuse they are actually able to feed both rear and front motor with all the power they can handle, making the theoretical combined hp rating actually achievable.
So yes, it could be that with the new fuse they are actually able to feed both rear and front motor with all the power they can handle, making the theoretical combined hp rating actually achievable.
Using 1/4 mile track calculators, it takes 174 more hp to get a 5100 lb car from 11.7 to 10.9. However, take that with a grain of salt. Those calculators assume typical ICE torque curves, so in reality, it will likely take fewer EV hp because they don't have narrow power band like ICE cars do. That said, ICE cars with good transmissions will do a good job of keeping that the engine near peak once you're already off the line. I wonder if these calculators factor in average shift times and such?
Ahh! That is a much better and more configurable calculator than the one I was using. Thanks!
stopcrazypp
Well-Known Member
True, but they never advertised a higher combined number and the reporter asked 691hp specifically, not the new higher number.
OK I just watched the interview again. Elon was clearly referring to the pre-Ludicrous P85D. His entire answer was: "Yeah, and it'll go [from] 0 to 100 kms in 3.1 seconds." It looks like he was actually quoting the 0-60 mph figure and forgot to adjust for the conversion to 100 km/h.
+ 1@sorka: damn you for making me want the upgrade nowwas hoping for the opposite effect from you
Similar threads
