Quote:
Originally Posted by HighlandPete
Not how BMW describe the Sport+ function. DTC is a function within DSC, and is activated in Sport+. Giving more freedom for wheel spin, but DSC is still active to mop up the mistakes.
This is BMW description for the F10. Sure it is the same in the F30.
In the F10 User Manual
HighlandPete
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This is how it worked in my 135i and how it's described to work with the F30.
DTC is "dynamic traction control", key word is "dynamic".
DTC is part of DSC. When DTC is engaged it allows wheel spin and rear end out to a greater degree before DSC steps in.
For practical purposes engaging DTC (pushing DSC button once) can help the car get unstuck if it's in snow and you need wheel spin to get the car out.
For fun, DTC (with either one push of DSC or sport+ engaged) allows the drive tires to spin on a hard launch as the ECU won't cut throttle in order to regain traction.
DTC also allows the driver to have some fun with a bit of "drifting".
It's not at the same level as turning DSC completely off as DTC will still intervene by braking and/or throttle cut if the rear swings past a certain degree.
DSC completely off will turn traction and stability completely off. This is the mode for experienced drivers as any mistake can't be helped by the stability system.
With my 135i this was easy to understand. If I want some wheel spin and some drift angle, but also have DSC step in if things get too far, then press the DSC/DTC button once and engage DTC. The rest of the car; steering, throttle stay as they are, as there was no choice. I had an MT 135i.
If I wanted full control and no stability ECU intervening, then I push the DSC button for at least 5 seconds and it's all off.
The F30 confuses the use of DSC and DTC as it ties drivers modes with it. If I'm in sport mode and I hold the DSC button, "DSC OFF" will light up on the dash. If I then turn DSC back on, drivers mode looks like it drops down to "comfort" mode, instead of staying in sport mode. Really odd.
Makes one wonder if they are still in sport mode if they turn DSC off while in sport mode. ARRRRGH!
When I'm in sport mode and turn DSC off it does feel as if I'm still in sport mode. BUT, my AT operation suggests otherwise, because once DSC is turned off, and I'm in sport mode, the trans will shift to 7th and 8th, which it won't do when driver mode is in sport. Conf*ckingfreakingfusing.
More testing is in order as I'm still not 100% positive what happens when I'm in sport driver mode and I manually turn DSC off.