New Launch Mode - firmware 2.9.40

[Andyw2100]

Enjoy the Froggo squat and launch, until we get Tesla squat and launch

View attachment 104558

View attachment 104559

I wonder what times did Froggo make, is the leap better with or without bugs inside?

These pictures are really misleading.

In the first picture Froggo is clearly sitting on a light branch. Were he to attempt to launch off that branch, the branch would not provide enough stability for Froggo to be able to push off in any significant way.

Yet in the second picture Froggo is clearly launching, and launching quite well, from a solid base!

THIS IS MISLEADING!

Perhaps you did not intentionally mislead, but I think we've been mislead all the same.

 

[lolachampcar]

WK,

No worries... I knew drawing current pulls battery voltage down from its at rest condition and more current pulls the voltage down even more as a function of internal resistance.

My posts had to do with questions about what I have heard described as skin charge or an artificially high voltage shortly after end of charge where by a little extra power is available from the battery. The phenomena I am referring to is not pulse demand power but strictly related to a very short duration of time following end of charging. I was just curious if there were some battery experts in the audience that were familiar with it.

 

[Auzie]

These pictures are really misleading.

.............

THIS IS MISLEADING!

Perhaps you did not intentionally mislead, but I think we've been mislead all the same.

Whatever I did it was intentional

 

[wk057]

WK,

No worries... I knew drawing current pulls battery voltage down from its at rest condition and more current pulls the voltage down even more as a function of internal resistance.

My posts had to do with questions about what I have heard described as skin charge or an artificially high voltage shortly after end of charge where by a little extra power is available from the battery. The phenomena I am referring to is not pulse demand power but strictly related to a very short duration of time following end of charging. I was just curious if there were some battery experts in the audience that were familiar with it.

Take a peak at some of the data I've gathered in my hacking thread. Specifically the updated rolling 20-60 data I parsed and updated (and haven't posted there yet): http://skie.net/uploads/rollingto60parsedv2.txt

I'm about to go for another drive and get some more logs of some actual 0-60's and stuff. Can't beat the CAN data. Instantaneous voltage and current at 100 Hz and speed at 10 Hz.

Gotta love the 100V drop at ~1200+A.

 

[stopcrazypp]

Guess I've just been getting annoyed with people misunderstanding how the battery works. You said power from the battery is P=IV, but it's just not that simple in the real world. Sure, measured downstream somewhere at an instantaneous point this is correct. But you can't use voltage measurements of the pack while not under load to determine power at a given amperage, which everyone seems to want to do with EVs to be able to say they can put out way more power than they're actually capable of, like when people quoted Elon Musk's 1500A number people jumped around saying the car could put out 600kW... which looks a lot like the math in a recent post on this very thread...

So sure, if you measure V and I while drawing some amount of P from the battery, then this is valid. But, for example, if I have a battery that reads 400V, and I want 400kW from it, you can't just plug in the numbers and say, poof 1000A are needed, or if I draw 1000A I'll get 400kW... since a battery is not an ideal voltage source. That's what I was getting at.

I know you are talking about my post, but I do know that the battery voltage sags under load and that the numbers I posted do not reflect the Tesla battery pack (neither does the motor voltage for that matter). I just thought it was unnecessary to factor it into the example to make the point that higher battery voltage (whether you choose to compare pre-sag or post-sag numbers) means more available power. So I just used them with clear caveats noted.

 

[wk057]

Anyone with the launch mode update have access to a CAN logger? Would love to try and parse the CAN3 data from a P85D, P85D, P90D, and P90D Extremely accurate performance data from the CAN bus

 

[fiksegts]

send me a link to a CAN logger, maybe I'll pick one up....

Anyone with the launch mode update have access to a CAN logger? Would love to try and parse the CAN3 data from a P85D, P85D, P90D, and P90D Extremely accurate performance data from the CAN bus

 

[lolachampcar]

WK put me on to a diagnostics connector and I have a couple on order. If they use the DB9 standard pin out for OpenCAN, my IXXAT tool will work. Give me a week and I'll know at which point you can borrow mine, buy your own or, if we move forward with our own, get a dedicated logger.....

USB-to-CAN V2

I have the V1 which has since been replaced with the V2. I use a freeware logging tool they used to have on their site but I can not seem to find it anymore.

 

[sorka]

I disagree. I can see at least 4 places in the car where this will save time.

1. Go pedal travel time. This is replaced by brake pedal release time instead, thus the only time saved will be the difference between the two. Probably the smallest gain.

2. Torque is already built up in the axles. The axles elastically deform under high torque, and it takes time for that torque wind-up to build in the axle before the torque being produced at the induction motor's rotor can reach the wheels. The launch mode will allow this torque wind-up to be pre-loaded, resulting in all torque produced at the induction motor rotor to already be transmitted to the wheel hubs.

3. Reduction gear lash is already taken up. This is not only the small clearances between gear teeth, but also torque deformation in the gears and splines.

4. I think this one is probably the most important. You have already established magnetic fields in the induction motor stator and rotor. The stator and rotor are magnetically permeable cores, and therefore have an inductance. Building current in them takes time because back-EMF resists the change in current. By pre-establishing the stator's rotating magnetic field and the induced rotor currents, you bypass this build-up time.

This is also why you only have 4 seconds to launch the car. The power going into the motor that is pre-loading everything is being 100% wasted as heat until the launch occurs, so you are heating the stator and the rotor pretty heavily. After 4 seconds, the temperature will have built up and you need to either launch or stop current flow.

We need to see an instrument cluster view of a launch mode with the Energy App displayed. I'd like to see how much power is being sent to the motors before the brake pedal is released.

1) The brake pedal is heavier with a lot more inertia. I'll bet it takes more time to release brake pedal than to stomp on the accelerator.

2) Not sure how this makes a difference. At most, you might have 1 degree of wind up which might net you a 0.20 inches of extra travel you'd get while unwinding.

3) For even less effect than #2.

4) This might have an effect and is likely bigger than all the rest. I think 1 will actually increase launch times.

- - - Updated - - -

People buy the P cars for a reason... It will certainly impress passengers more than a 50-70 time. As for real-world, well that's up to the driver.

The car has enough power to pass any other car like it was standing still, it's only a problem if you're racing some other semi-exotic. I'd recommend driving an any-car sometime, like a typical honda civic with an engine less than 2 liters, or a subaru legacy wagon, and you can wonder how they manage to even merge onto the highway.

Does an RS7 count as semi-exotic? Even the E60 70-90 passing of 2.4 seconds is only matched by the Tesla with Ludicrous and max battery power enabled.

 

[wk057]

send me a link to a CAN logger, maybe I'll pick one up....

The only one I've seen so far that works out of the box with the right connector and all is the one from EVTV: EVTV Motor Verks Store: SavvyCAN for Tesla Model S, CAN Tools, TeslaCANKit

It's the one I've been using with live vehicles for logging.

lolachampcar might have a less expensive solution soon, however.

 

[lolachampcar]

fiks,
I forgot to mention that IXXAT produces a majority of the tools used for most manufacturers field calibrators. This is how I was exposed to them. Other vehicle dynamics employ the tools as well. My Zero even uses IXXAT as one of its options for reflashing the speed controller and related system boards.

 

[sillydriver]

1) The brake pedal is heavier with a lot more inertia. I'll bet it takes more time to release brake pedal than to stomp on the accelerator.

While that's true, I assume the car is at least primarily brake-by-wire. After entering launch mode the system may be programed to release the brake entirely almost instantly once it detects the pedal being side-slipped.

 

[lolachampcar]

No data to back this up but side stepping the brake feels an awful lot faster to me than getting a running go at the throttle pedal.

 

[Andyw2100]

I'd love to see a video from the outside of the car of the rear end squatting when enabling launch mode!

Everyone's a cinematographer

But that actually would be cool to see.

While we're directing: Leave the camera near the ground behind one of the rear wheels so you can see the side of the car as it launches.

I don't believe I've seen this posted in this thread, but apparently benjiejr did make the video he wanted to see: P85D Launch Mode Demo

 

[sillydriver]

I don't believe I've seen this posted in this thread, but apparently benjiejr did make the video he wanted to see: P85D Launch Mode Demo

It's interesting to watch the rears twist what looks like a couple inches and pull the rear of the car down while the fronts hold. Thanks for the video pointer.

 

[AWDtsla]

I don't believe I've seen this posted in this thread, but apparently benjiejr did make the video he wanted to see: P85D Launch Mode Demo

Sweet!

I'm getting the feeling that slip start may help here. Heard 0 complains from the tires.

 

[lolachampcar]

My P85D left 63' of very light rubber dusting on tarmac and chirped on concrete up to about 40 to 50 mph. Tesla has most certainly changed allowable slip angle in launch mode as the car did not do this prior to the update.

 

[yak-55]

My P85D left 63' of very light rubber dusting on tarmac and chirped on concrete up to about 40 to 50 mph. Tesla has most certainly changed allowable slip angle in launch mode as the car did not do this prior to the update.

So, a little more launch drama :smile:, and a very little reduction in 0-60/quarter . More engineering for marketing buzz instead of engineering for performance? I liked it better when engineering was ahead of marketing/promotion.

 

[Bill D]

My P85D left 63' of very light rubber dusting on tarmac and chirped on concrete up to about 40 to 50 mph. Tesla has most certainly changed allowable slip angle in launch mode as the car did not do this prior to the update.

It's interesting in Benjamin's video that it doesn't leave a spec on the tarmac. It looks a drama-free as before.

 

[ArtInCT]

It's interesting in Benjamin's video that it doesn't leave a spec on the tarmac. It looks a drama-free as before.

I think Lola has some light weight wheels....