Well it's raining today and I've just had a play with M Track Mode enabled. In this mode DSC doesn't cut power when the wheels spin in a straight line. It also allows some slip so you can get the car sideways and it will still allow full power - until a threshold is reached. I'm not sure what the angle is, but it does allow a fair amount! Obviously you should use this mode on a race track and I can't recommend it be used on the road
This mode is what our cars have been screaming out for and I've no idea why BMW don't enable it from factory!
I'm wondering whether this is actually just DTC and not M Track Mode. Googling both seems to suggest they are similar anyway. Either way, this mode makes the car much more driveable, especially in the wet. Obviously disabling DSC gives the best experience, but for those of us not skilled enough enough to drive with it disabled, this mode is an excellent half way house.
So to enable it on your car. The procedure is relatively straightforward and assumes you are relatively proficient using Microsoft Windows...
Firstly you need to purchase the correct cable and obtain the software. This can be found on eBay and some sellers also provide a DVD with all of the necessary software. Buying one with the software supplied might be the best choice if you're not overly comfortable installing drivers and software in Windows. The cable required is a BMW OBD Diagnostics cable but check the one you get works with the Z4 (E85). It needs to use the K-Line protocol, but you could get a cable which supports the newer DCAN protocol too (in case you upgrade to a newer BMW and wish to future proof yourself). You also need to ensure the DATEN files are relatively new. I think v50.2 had the last revision of changes for the E85. Perhaps check with the supplier which version they are sending you.
The software you need to use is NCS Expert and there are lots of guides online explaining how to use it to add Option Codes to your cars Vehicle Order (VO) list (i.e. to retrofit features), or to code changes to existing modules (i.e. enable remote roof opening/closing, beep on lock etc.)
Once you have NCS Expert installed and working, you need to enable TDR on the MK60.C20 module:
Connect the cable to your car's OBD port and turn on the ignition...
1. Load NCS Expert.
2. Load an ExpertMode profile with Manipulation enabled.
3. Hit “FG/ZCS/FA” - might be "VIN/ZCS/FA" depeding on your NCS Expert version
4. Press “ZCS/FA f. ECU”
5. Select E85 in the box that pops up
6. Click OK with AKMB highlighted
7. FG and FA field will populate after a few seconds
8. Press Back
9. Click “Process ECU”, highlight the MK60 module and click OK
10. Change CBD-Name MK60.C10 to MK60.C20 and Click OK
11. Click "Change Job" and choose CODIERDATEN_LESEN
12. Click “Execute Job”
13. Browse to C:\NCSEXPER\WORK
14. Look for FSW_PSW.TRC and open it in notepad.
Look for:
TDR
nicht_aktiv
and delete the nicht_ leaving just aktiv
15. Save the file as “FSW_PSW.MAN” - (make sure it's not called FSW_PSW.MAN.TXT)
16. Click "Change Job" and choose SG_CODIEREN
17. Click "Execute Job"
NCS will then code your car and you should see "Coding Ended". Then turn your iginition off/on and pressing DSC will enable the DTC lamp (M Track Mode) and holding will disable DSC altogether.
There are lots of guides online which explain using NCS Expert in more detail, and it might be a good idea to read these and get more familiar before you attempt this yourself.
