New Launch Mode - firmware 2.9.40

[sandpiper]

The car does apply power against drive line lash and the tire side wall but this is really not that much torque. The launch itself fully uses the tire side wall and there is absolutely nothing that would give me any hesitation WRT drive line issues.

Race cars and ICE with launch have difficulty when the rotational inertia builds then is abruptly stopped. Spinning the tires on corner exit then gaining traction has snapped many an input shaft or half shaft for me. Street car ICE launches where they spin up the engine then dump that inertia to the wheels is, likewise, hard on components. Tesla does not spin anything up and their traction control is so good that there simply is not enough time in the slip condition to build much drive line momentum. I do not see a problem (and, having said that, I will not likely promptly break my car :0 )

Agree. Many years ago I worked for a company that manufactured transmission shafts. In general, loads are far higher when stomping on the brake than when accelerating. An EV is a different game, of course, because you have so much less inertia in the drive-train.

- - - Updated - - -

This "Squat" has me intrigued. If the brakes on all four wheels were fully engaged while staged, there would be no squat. It makes me wonder if Tesla's Launch Mode only engages the front brakes while the rear motor applies static torque to the rear wheels pressing backwards against the ground. Drag racers with a line-lock engaging only their front brakes while their ICE engine revs up against their torque converter get a similar squat while staged.

This is what I was thinking. If there is a noticeable "squat" then you can't possibly have all 4 brakes engaged.

 

[sillydriver]

Perhsps the front brakes are locked, but there is not quite enough power to the rear wheels yet to make them spin while the car sits still. Otherwise one would initiate a burnout.

Yes, the torque must be very finely tuned to flex and pre-load the rubber without breaking traction - something that could probably only be done with the precise control an EV has.

 

[lolachampcar]

A mass market long range production BeV that-

Squats

Launches

Great stuff

 

[dailydriver]

First, there is no way my launch control is shaving .5 seconds off the 1/4. The best it is doing is POSSIBLY, and that is a very big possibly, taking .1 to .15 off the 0-60.

I totally agree, but I guess I am hoping that this software release also includes some other upgrade that will make up that difference.


P.S.

I see that you are on the McLaren Life forum too. I just traded my old Model S Signature on a 12C.

 

[sillydriver]

Okay, so does anyone here with either a P90DL or upgraded P85DL have, or do we know any such owner who has, 2.9.40, which seems to be limited release. If not, maybe owners who live conveniently near their SC can call and see if the SC can install the update if they bring it in.

The odd thing will be if no one on this board with a ludicrous-mode car ends up with 2.9.40, only insane mode cars. That would imply this launch feature is part of a package for ludicrous cars that they have not fully released.

 

[P85DEE]

I totally agree, but I guess I am hoping that this software release also includes some other upgrade that will make up that difference.


P.S.

I see that you are on the McLaren Life forum too. I just traded my old Model S Signature on a 12C.

Less than 4 tenths has to be shaved from the current best to reach 10.9x.

Perhaps there is more which happens after the launch, especially since a 122.x trap speed was also mentioned in that Motor Trend article.

That said, the car which ran the 11.38, did so with a 1.6xx 60 ft time.

I doubt we see 1.5xx 60s out of this car with this new launch mode.

This again makes me wonder what happens through and after the launch.

 

[lolachampcar]

daily,
I used to do the F car V8 thing and drifted away from it. I got the 12C to "park" the sales tax credit when I disposed of the P+ four months before getting the PD. Tesla was offering $9K less than wholesale for my P+ and I'd be dammed if they were going to get the car after refusing to do a courtesy trade and telling me the only way I would get the FL sales tax credit was to trade them the car.

Anyway, I had long since sold my last ICE sportscar having lost interest. The 12C changed all that. It is a real hoot and one I love driving several times a week. Never would have done that with an F car. It was so much fun that I simply kept it when the PD came in. Still have it and still drive it several times a week. Bet you are lovin yours as well.

 

[fiksegts]

I think we could dip into the 1.5x range, BUT that's not enough to get into the 10's, the traps must be in the low 120's as well.. I'm hoping to swing by my SC to get the update pushed to my car...

Less than 4 tenths has to be shaved from the current best to reach 10.9x.

Perhaps there is more which happens after the launch, especially sine a 122.x trap speed was also mentioned in that Motor Trend article.

That said, the car which ran the 11.38, did so with s low 1.6xx 60 ft time.

I doubt we see 1.5xx 60s out of this car with this new launch mode.

Thus us agau makes me wonder if hat happens through and after the launch.

 

[malcolm]

Part of the concern is that Tesla are trying to do everything through their one vehicle. So they've made a sedan which out-accelerates their own Roadster! Yes that is a bit daft, but electric drives allow for this sort of thing so why not? The technology is there and I can't see any other manufacturer pushing it yet.

 

[fiksegts]

congrats on the 12C! I had a 12C for a couple years and recently traded for the 650S, amazing cars....

I totally agree, but I guess I am hoping that this software release also includes some other upgrade that will make up that difference.


P.S.

I see that you are on the McLaren Life forum too. I just traded my old Model S Signature on a 12C.

 

[dailydriver]

daily,
I used to do the F car V8 thing and drifted away from it. I got the 12C to "park" the sales tax credit when I disposed of the P+ four months before getting the PD. Tesla was offering $9K less than wholesale for my P+ and I'd be dammed if they were going to get the car after refusing to do a courtesy trade and telling me the only way I would get the FL sales tax credit was to trade them the car.

Anyway, I had long since sold my last ICE sportscar having lost interest. The 12C changed all that. It is a real hoot and one I love driving several times a week. Never would have done that with an F car. It was so much fun that I simply kept it when the PD came in. Still have it and still drive it several times a week. Bet you are lovin yours as well.

I kept my Sig instead of trading it in on the P90D because, like you, Tesla was not offering enough to make sense. I had it for several months weighing my options (which included possibly selling it outright). The option that emerged as the best was trading it in on a 12C since they are such a great value right now. You're right, I absolutely love it and can't wait to get some track time in the spring. I thought I wanted a 360 or 430, but they don't compare at all (driving, but style is another matter). The 458 is a great car, but the 12C is more subtle and a better road car.

Sorry for the brief hijacking of the thread. We are done here.:redface:

 

[Bill D]

But what you're saying about the front brakes only being engaged with this new feature, makes sense.

Perhsps the front brakes are locked, but there is not quite enough power to the rear wheels yet to make them spin while the car sits still. Otherwise one would initiate a burnout.

During the squat, the front brakes alone would hold the car still even if the rear motor was applying up to a couple thousand pounds of static force pressing back against the pavement. At the same time, the front motor could be applying any amount of static torque to the front axle awaiting release of the brake.

 

[lolachampcar]

Two more data points.
I took my car by the Service Center today as they had not seen launch control. My car chirped hunting for grip past 60 mph on concrete.
Second, I did some launch demos on tarmac and left 63 foot long dual rubber marks. These were not the real dark ICE type tires on fire marks but a very light dusting of rubber.
Launch mode most certainly modifies allowable slip angles in the traction control because my car did neither of these things before the advent of launch control.

 

[thegruf]

^ now that sounds properly interesting.
Tesla's advantage over ICE is the finesse they can control the motors torque compared to trying to modulate the intertia of a thumping big V8.
Somebody needs to get some drag tyres on and see what it can do

 

[ArtInCT]

Two more data points.
I took my car by the Service Center today as they had not seen launch control. My car chirped hunting for grip past 60 mph on concrete.
Second, I did some launch demos on tarmac and left 63 foot long dual rubber marks. These were not the real dark ICE type tires on fire marks but a very light dusting of rubber.
Launch mode most certainly modifies allowable slip angles in the traction control because my car did neither of these things before the advent of launch control.

Wow... they are just on the edge with their traction control. Were your tires warm when you left dust? And what tires are you running? A staggered setup or square? This is pretty amazing...

 

[lolachampcar]

Square Michelin Pilot Super Sports on 20" rims. The PSS are stickier than PS2s while having the added benefit of being cheaper My rims are about 10 lbs per corner lighter than stock Tesla rims.

It was Florida mid day with ambient temps around 85F and the tires "cold".

2015 P85D
255/40 ZR 20 (Porsche option with square shoulders)

 

[AWDtsla]

Two more data points.
I took my car by the Service Center today as they had not seen launch control. My car chirped hunting for grip past 60 mph on concrete.
Second, I did some launch demos on tarmac and left 63 foot long dual rubber marks. These were not the real dark ICE type tires on fire marks but a very light dusting of rubber.
Launch mode most certainly modifies allowable slip angles in the traction control because my car did neither of these things before the advent of launch control.

Looks like my tire budget will need a bump ;-)

 

[P85DEE]

I think we could dip into the 1.5x range, BUT that's not enough to get into the 10's, the traps must be in the low 120's as well.. I'm hoping to swing by my SC to get the update pushed to my car...

Yes, I'm aware that a 1.5xx 60ft time by itself still would not be nearly enough to get you from an 11.38 to a 10.9xx. About the most that one can hope for with a .1 second improvement in 60 ft time would be about .15 seconds improvement in quarter mile elapsed time.

Thats why I'm hoping that there is a bit more to this update than just a hole shot improvement.

I have a good feeling.

 

[Andyw2100]

Thats why I'm hoping that there is a bit more to this update than just a hole shot improvement.

I have a good feeling.

I hope you are correct.

Are you concerned at all, though, about the fact that Max Battery Power must only be enabled, and not in the ready state, for Launch Mode to be activated? I admittedly know little about this stuff, but I would think that since Tesla has said that Max Battery Power is a requirement for the very top performance, that if their top performance metrics are now going to be delivered as a result of Launch Mode, then it would stand to reason that Max Battery Power would have to have reached the "ready" state, and not just be enabled. This makes me a bit dubious about any additional performance enhancements being tied to Launch Mode. That's not to say they aren't coming some other way, of course.

Just my thoughts.

 

[lolachampcar]

Andy,
I'm a bit confused by your post. As I understand it, Max Bat on is a prerequisite to enabling the launch pedal dance. The battery does not have to be in its optimum condition for the launch to be available, max bat just needs to be on. There are conflicting opinions/data regarding the effectiveness of max bat ready so the jury is still out on that but launch only requires that it be enabled.