In launch control mode you put the car in Sport+, put your foot on the brake, quickly floor the accelerator and if it goes into launch control the engine will go to 6000-6500 with the fluid clutches not engaged. When you take your foot off the brake, the clutches engage partially which puts the engine at about 4500-5000 where the torque curve comes in, then as the car accelerates they fully engage. If you don't put the accelerator down fast the clutches engage immediately and tight just like when you are taking off with a normal amount of acceleration, providing a non-slipping clutch which syncs the engine and transmission RPM immediately.

In what I call the mini-launch control (which I've never found documented) you put the accelerator down quickly in any mode (normal, sport or +, without putting your foot on the brake) and the engine will accelerate to 3500-3700 RPM as you take off. This provides about a .7 G longitudinal acceleration, it's a lot of fun and doesn't draw as much attention. You don't have to put you foot all the way down, but you do have to put it down quickly. I typically use half throttle. In the 997 PDK if you did this, the clutches would lock up immediately and the RPM would not rev to 3500, lugging the engine down.

Finally, if you use this technique but only do 1/4 throttle you avoid the transmission's tendency to shift early. All this is using Shell 93 fuel. If you use 91 the car may detect it and change the fuel / ignition timing such that the engine won't spin up as fast causing you not to be able to use the above techniques.

ChuckJ