Thats a new one ....
With no TC engaged in launch mode , that back end is gunna be all over the place on the up shift

 

Very odd behavior!

If you are in Track for the suspension, the TC light "off" shows up BUT, there is still some TC in the background. You have to go thru a 5sec press of the Active button and BOTH the Aero & Manual buttons to disable ESC fully. TC and ESC are two different things but also work together. In a straight line the TC being off should only allow wheel spin and not any crazy sideways action without ESC being off! That said, I have done several launches in my 650 and nothing like that has ever happened. My car is bullet straight during launch and subsequent shifts no matter how long I am "in it"...

 

Interesting, so you do get a TC alert on the left hand screen during launch control? That may have been what happened. It’s possible the surface I launched on wasn’t completely clean or had a slight camber. I’d imagine the lack of LSD will potentially cause some asymmetrical power delivery on non-perfect surfaces. Will have to try it again and report back. Thanks for the context!

 

There is a TC off warning lamp if you put the ESC into dynamic mode, TC is still active but is less restrictive. I think it’s industry standard to turn this lamp on if the TC is in sport.

 

When my 650s was stock, while I never used launch, I virtually always had the "active" button on with performance always set on "T." The Aero setting on "T" surprised me as to how far I had to chase the back on turns, so I stopped using Aero T on roads with many turns. I seem to recall that when Aero was set on S, on some turns, I'd get wheel spin, but the engine basically stopped. I always used active and S for Aero, T for performance. My first day surprised me as to how much wheel spin there was on the Corsa tires well into 2nd gear. Loads of fun.

I do have an M-engineering tune, and I virtually always use S for Aero and T for Performance. M-engineering does and excellent job of doing as much as possible to maximize acceleration. I'll break traction, but it's very controlled, or I've just been lucky. Probably lucky. Exact same settings as stock.

TC intervenes well into triple digits on cold R888's, 315mm. But once the tires are at 120f or hotter, much less of a loss of Traction, but it's still there below 80.

 

When my 650s was stock, while I never used launch, I virtually always had the "active" button on with performance always set on "T." The Aero setting on "T" surprised me as to how far I had to chase the back on turns, so I stopped using Aero T on roads with many turns. I seem to recall that when Aero was set on S, on some turns, I'd get wheel spin, but the engine basically stopped. I always used active and S for Aero, T for performance. My first day surprised me as to how much wheel spin there was on the Corsa tires well into 2nd gear. Loads of fun.

I do have an M-engineering tune, and I virtually always use S for Aero and T for Performance. M-engineering does and excellent job of doing as much as possible to maximize acceleration. I'll break traction, but it's very controlled, or I've just been lucky. Probably lucky. Exact same settings as stock.

TC intervenes well into triple digits on cold R888's, 315mm. But once the tires are at 120f or hotter, much less of a loss of Traction, but it's still there below 80.

I assume when you say “Aero” you mean Handling - which in T does have ESC intervene much less but not zero. So yes you can get the back to step out and drift and it is left to your own skills to control. And Performance modes only change the automatic shift points so does nothing if you are in Manual.

You are confusing the action of pressing the buttons labeled Aero (which only sets the spoiler up by default) and Manual (which enable manual shifting). These are different from the N, S, T around the button.

 

I havent checked it...bit tin the manual for the 720s, it says something to the effect that TCS is limited, until you either shift or lift off the throttle, then it presumably goes back to whatever your settings are.

I think its just indicating that the programming has control of traction until the launch mode process is either finished or aborted or completed

 

groesbeek is correct. Handling on the left and Performance on the right. On Handling is the Aero, and Performance has the Manual.

I apologize.

 

Well this is what is says in the 650s manual. Never tried it myself (I prefer track driving), but presumably it’s a different set of TC parameters.

“NOTE: Whilst in launch control, the vehicle will carry out automatic gear shifts, and optimise traction. It will continue to do so until launch control is aborted. “

The manual does emphasize to only use launch control on track and when “the prevailing conditions are suitable for performing maximum acceleration maneuvers”, implying that it’s not going to save your ass if you are not respecting the conditions! 😉

 

I agree with groesbeek, track driving is the most challenging, rewarding, etc. My work was 6 - 7 days per week. I have tracked my 944turbo years back, but on one of the few days I had off, my PCA comrades would not let me track either the 944turbo or my 650s. Then I moved. I miss Willow Springs and, and I believe the new owners will update the facility.

I've posted the dyno sheet I received from M-engineering, so I won't dwell on that data. RWHP is challenging for me to understand as opposed to engine HP, SAE net. I believe it's J1349. SAE has well explained HP. Manufactures however, are not held to SAE net.

We live in a time where the ICE were expected to be at the end of production, but that has changed, and there are incredibly powerful cars from the factories; 9 second, 1,200hp, for anyone with enough cash.

I prefer to find out exactly what 1,000hp means in terms of acceleration. While my 650s has 3 maps, without the data to support a RWHP number, I struggle with the accuracy.

I have not used launch, as I feel that there are aspects of the car that may break, tranny, shafts, etc.

I found a deserted paved place. I set up my RaceBox accelerometer, and stepped on the gas, using the middle map. While the tires were at 96f, the traction control intervened until 120, or higher. 10.48 1/4 mile is not very good, but trap speed was 149.7. Acceleration from 60 - 130 was 4.68. Again, not good. 60 - 170 was 10.6, very strong. Acceleration from 130 - 170 was 5.62. I was satisfied. M-engineering numbers for my car at World Motorsports are accurate. The last 2 pulls, above are quicker than an SF-90. I neglected to mention that the last two pulls, were are quicker the the 918, P1 and LaFerrari, but an SF-90 generally out pulls a LaFerrari. Yes, I know the Trinity are the approximate age of my 650S. Side note, my personal opinion is that the Laferrari is, as of now, the most beautiful Ferrari made. It's subjective.

I'm certain that many other McLarens are far more powerful, but this is a 3.8L. I was braking aftet 170, and the last time I applied the brakes was at 175.4, and I rolled through the 1/2 mile in 15.9 @ 147.

Please believe me, I'm simply the keeper of a car, which was completely enhanced by those who know these cars well. The person who managed every step of this project is Eric Cheney @ Voodoo-design.com. Eric is brilliant and his exhaust work is also the finest I've ever seen. Eric knows McLaren cars incredibly well, and he lnows all other supercars.

Sorry about the long post, but for me, I do find the acceleration to be the most unadulterated fun.

Im not sure exactly why, but McLarens are modified far more than other supercars, save for, possibly the GT2 RS or the turbo S. Where else could we do what we're doing?