Launch Control functionality

[sbash]

I was under the impression that when using launch control, torque was not applied to the drivetrain until letting off the brake. When I use it, it functions similar to "brake torquing" a vehicle. From what I can tell, launch control only changes the shift program, shifting earlier and faster when gong through the gears.

I'm fairly sure that I'm entering into launch control because it gives me a light indicting that it is enabled. My procedure is: drive the car several miles to get it warmed up, put transmission into S3, starting in 1st gear, hold brake and quickly depress the accelerator to the floor.

As soon as I apply throttle, even though it shows that I'm in launch mode, the car lunges immediately. Is this normal?

[elisiX]

I haven't tried this yet on my car, so i'm not sure whether that is normal or not, however I thought you also had to be in MDM?

[sbash]

Originally Posted by elisiX

I haven't tried this yet on my car, so i'm not sure whether that is normal or not, however I thought you also had to be in MDM?

Oh yeah, you are correct. I have M2 programmed for the MDM change. I just forgot to put that in the steps.

[elisiX]

I wonder if it's the fact that it is not a true DCT transmission.

My Audi SQ5 was similar in that it had too much torque for the DSG gearbox.

Therefore when you used Launch Control, it acted as you describe.

[onfireX5]

Hold the footbrake down hard and it will hold the M and the rpm will settle around 2700. Then let it rip.....

[fyim]

Originally Posted by sbash

I was under the impression that when using launch control, torque was not applied to the drivetrain until letting off the brake. When I use it, it functions similar to "brake torquing" a vehicle. From what I can tell, launch control only changes the shift program, shifting earlier and faster when gong through the gears.

I'm fairly sure that I'm entering into launch control because it gives me a light indicting that it is enabled. My procedure is: drive the car several miles to get it warmed up, put transmission into S3, starting in 1st gear, hold brake and quickly depress the accelerator to the floor.

As soon as I apply throttle, even though it shows that I'm in launch mode, the car lunges immediately. Is this normal?

It's normal. I experienced the same thing over and over

[M6-Coupe]

Originally Posted by sbash

I was under the impression that when using launch control, torque was not applied to the drivetrain until letting off the brake. When I use it, it functions similar to "brake torquing" a vehicle. From what I can tell, launch control only changes the shift program, shifting earlier and faster when gong through the gears.

I'm fairly sure that I'm entering into launch control because it gives me a light indicting that it is enabled. My procedure is: drive the car several miles to get it warmed up, put transmission into S3, starting in 1st gear, hold brake and quickly depress the accelerator to the floor.

As soon as I apply throttle, even though it shows that I'm in launch mode, the car lunges immediately. Is this normal?

You are correct. It's "brake torquing" which is called Launch Control by BMW marketing. In fact Launch Control is kinda meaningless here since there is no clutch involved to drop the torque (an power) down at certain RPM where the maximum torque is available... If you try the launch control with proper clutch based transmission (such as M5/M6 DCT) you can see the difference... it's totally different feeling