Playing around with VBOX Sport.... 0-60 times...

[thegruf]

Correct. 0.357 seconds to move 1 ft.

Actually that's an interesting point ...

Why does it take 0.35seconds to gather it skirts up and fly?
There seems no reason for the electronics/motors to delay, though the software may control it a bit for driveability/traction

Speculation - there is a delay whilst the coolant pumps accelerate the battery coolant through the pack for max cooling?

 

[sorka]

I've seen the times range any where from 0.25 to 0.37 seconds on the 1 ft rollout. These are typical times for street tires on an AWD car.

- - - Updated - - -

I've seen the times range any where from 0.25 to 0.37 seconds on the 1 ft rollout. These are typical times for street tires on an AWD car.

 

[thimel]

If the car immediately started accelerating at 1 g, it would take 0.25 seconds to travel one foot.
This comes from the formula distance = 1/2 acceleration*time**2 where the acceleration of gravity is 32 feet per second per second.
So, the one foot roll out times above mean the car is actually doing this for the 0.25 second time, or ramps up to 1 g such that 0.12 seconds ares wasted for the 0.37 second time.

 

[Duma]

So, the one foot roll out times above mean the car is actually doing this for the 0.25 second time, or ramps up to 1 g such that 0.12 seconds ares wasted for the 0.37 second time.

Also consider that there is a human foot jamming down on the accelerator, so the control signal does not instantly go from 0 to maximum. The driver's foot is moving for some fraction of a second before the accelerator is at maximum. Which is not to say that there isn't also some additional delay added by software smoothing multiple samples of the accelerator signal to smooth out the noise associated with any analog component, such as pedal motion.

 

[LetsGoFast]

If the car immediately started accelerating at 1 g, it would take 0.25 seconds to travel one foot.
This comes from the formula distance = 1/2 acceleration*time**2 where the acceleration of gravity is 32 feet per second per second.
So, the one foot roll out times above mean the car is actually doing this for the 0.25 second time, or ramps up to 1 g such that 0.12 seconds ares wasted for the 0.37 second time.

I don't know for certain, but the problem is likely one of the limited grip between the tires and the road. The traction control will be pulsing the power for milliseconds at a time to avoid wheel spin, which will be most evident in the first few feet.

 

[sorka]

Here is one for a P85+. I did several runs at 90% and several runs at 60%. There was no difference in power between 60% and 90% nor was there a difference in 0-60. The P85D lost 43 hp at the wheels between 90% and 65%. The power peaked at 437 at the wheels which is within a few ponies of typical P85 runs on Dynojets. Notice how the shape of the curve is identical to the S85 but just more of it.

0-60 with 1 ft rollout:
60% was 4.012
90% was 4.096

This is just about exactly a 1 second difference if the P85D is fully charged. The P85 doesn't have to be fully charged to get it's best time. I didn't measure at lower SOCs, but I did run the P85+ down to 40% at one point and didn't feel any pullback in power.

 

[jkn]

Interesting measurements, but something is wrong: Acceleration rises from 0 to max in 0.9 s. Why so slowly? In test made by consumer reports test acceleration reaches max value in 0.3 s.

Tesla Model S P85D Test Results - Consumer Reports

Perhaps you are too gentle with pedal?

 

[sorka]

Interesting measurements, but something is wrong: Acceleration rises from 0 to max in 0.9 s. Why so slowly? In test made by consumer reports test acceleration reaches max value in 0.3 s.

Tesla Model S P85D Test Results - Consumer Reports

Perhaps you are too gentle with pedal?

Not sure where you got that. They never say that in that article and their own vbox chart from their hellcat comparison shows exactly the the same thing as my vbox runs do.

That said, if you're going at a static speed above 36 MPH and then floor it, it takes 0.3 seconds to reach maximum power. That's why if you test 70-90 MPH on a P85D with 70% SOC, it takes 3.0 seconds flat to to pass through the 70-90 MPH range if you start below 50 MPH and you're already accelerating at maximum, but if you're going exactly 70 MPH and then floor it, it takes 3.2 seconds from the time the vbox starts to detect a change in velocity to the time you hit 90 MPH.

 

[jkn]

Not sure where you got that. They never say that in that article and their own vbox chart from their hellcat comparison shows exactly the the same thing as my vbox runs do.

Consumer report video linked above at 3:49
Acceleration of Tesla rises from 0 to 1 g in about 0.3 s, stays roughly at 1 g up to 1.6 s.

Comparing with yours posted 2015-07-13, 02:26 AM (This seems to be my local time. I posted this 9:57 PM, now editing to add this comment.)
0 g at 255.4 s
1 g at 256.4 s 1.0 s
drops < 1 g at 256.9 s 1.5 s from start

So largest difference is at start. I can imagine several possible reasons.

 

[sorka]

They may have said that in the video eyeballing it, but it doesn't reach maximum until almost a second from their own vbox chart same as mine. Don't be fooled by the slope. My x-axis is only showing half as much time for the same distance on the chart. If I compress it to show 8 seconds on the x-axis with the same aspect ratio, it looks nearly identical to their graph.

 

[jkn]

They say 0.3 s from 0 to 1 g. At 3:49 in video they also show acceleration graph. It clearly shows about 0.3 s from 0 to 1 g. Seconds are clearly marked on X-axis and g's on Y.

 

[sorka]

Now you've got me looking closer comparing the shapes :smile:

So their peak of 1.02gs doesn't quite match my peak of 1.06 gs. Also, their 0 time index doesn't quite start at 0 g's either.