I have "launched" the car a couple of times now. I have tired it with traction control off and on. You step on brake wind up the engine and let her go. It make a fantastic sound. Leave the line like it was shot out of a gun. 20 feet into the launch, it stutters gabs and goes, stutters, grabs and goes. I think it is having issues with traction. Seems like I could be faster if I just bury the throttle. I thought the whole point was that it manages traction to give you the best launch. Sure does seem like it.

M

 

I originally thought launch control was a sales gimmick (to boost 0-60 times), and I still do when the car has a manual clutch. But with cars having automated clutches, we lose some control over how much slip, what RPM's etc, and that all essential stoplight race take-off.

I have not used the 991 launch control yet (haven't driven one). From other launch controls I have used, though, I have not seen an adjustable traction control (i.e. smart-mode so there is a perfect launch every time). Traction control would be selected in some other way. The point of the launch control is to raise RPMs and mimic a high RPM clutch dumps, not give you traction. In fact, I've seen where using launch control actually reduces traction and forces traction control to intrude and kill all of your fun...

 

If it produces the best possible (consistent) 0-60 times then it really isn't a gimmick.
I wasn't saying that it should increase traction. I was under the impression that it would use what traction was there to the limit. Thinking a perfect launch would be a constant little bit of wheel spin. What I think is happening is that it takes off then the wheels break loose and the engine cuts power to grab traction then we go thru the cycle a couple of times. This to me does not seem like the perfect launch.

 

I think it's a plot by the tire companies and Porsche to encourage us to hammer our cars so we have to buy replacements sooner.

 

I have never experienced your symptoms as such as "stutters, grabs, and goes" through my many launches and on many different surfaces (track concrete, old asphalt, and new asphalt). I feel only a full and constant acceleration with power continuously building - I have done this on the track from standstill to over 140mph (backed off due to first turn turn). I do have a C4S (w/ PDK) so there is that difference. I experience the initial rush of G's for about 8-10 seconds but the power build is stable and constant. Your descriptions sound odd to my experience. Have you tried different road surfaces and found the same issue?

 

I would actually take the OP's car in for a checkup; there might be something wrong... even the old school single clutch SMG (E46 M3) pulled hard and consistently via LC. The twin clutch should just pull (hard) with a little blip at redline... There actually is some processing going on to monitor wheel spin; can light the tires up with TC off and a heavy throttle. LC chirps, digs and pulls until you are scared.

 

Are you sure that you engaged Sport + and Launch Control? Did it light up on the cluster? The first time I tried it on the test drive, it didn't work and then I made sure to engage LC and it worked as advertised.