Here Dave.... you seen this yet?
Can't get the link to copy right. Click on it and add the #! at the end. My computer has been acting up all day.
Also, have you read this?
Why would you want the new Launch Control system on the all-wheel-drive 2014 Grand Cherokee SRT®? It would seem that there is so much traction that all you have to do is floor the throttle and go. Sure, the Grand Cherokee SRT will leap off the line, pinning you back hard against the seat while it rockets down the drag strip. Performing a perfect launch every time is nearly impossible, even for professionals. Nailing the exact launch RPM ever time is nearly impossible without Launch Control.
"When we showed the car to the press in 2012 the question was, 'How do I get the best acceleration?' And it's, 'don't use paddles, put the car in Track Mode, rev it to 1100 RPM-but not 1300 RPM and not 900 RPM,'" said SRT development engineer Jeff Roselli. "We had to give a very long dissertation on how to do that. So now with Launch Control the button is right next to the Selec-Track® dial on the center console, and it all happens automatically. You basically stop the car and hit the button."
The Launch Control button activates a system that will optimize every possible setting for maximum acceleration off the line. Launch Control will prompt you to hold the brake, straighten the steering wheel and apply full throttle. As soon as you apply over 75 percent throttle the car goes into Launch Mode. The system will change the suspension settings to firm, turn off the traction control, stability control switches to Track, and change the torque split to 70-percent rear, 30-percent front — all with a simple touch of a button.
When you go to full throttle and the engine goes directly to optimum RPM, somewhere between 1400 and 2000 RPM and holds until you lift off the brake. When you do that, the car leaves the line, accelerating as hard as possible with maximum torque and minimum tire spin. As Roselli puts it, "all hell breaks loose." As soon as you do your run and you lift off the throttle all of those functions go back to whatever Selec-Track mode you were in. It is a very temporary thing. You do a fast time and it just reverts back.
"Launch Control is tuned for the drag strip," according to Roselli. "We have the threshold set so you can pre-stage and stage it's only when you hold the brake and go over 75-percent throttle that the Launch Mode is ready to roll. And if the brake isn't on and the steering wheel isn't straight the Launch Control button will flash at you. When everything is right, the light goes solid and you can go."