The ASC is a function of the abs system and can be had with an abs control module change (Done on mine CONTROL UNIT ABS/ASC 34521090155 $1,489.86), the effect can be pretty harsh and when combined with an lsd sometimes it can feel as if there's a locker back there.
The traction control part is related to EML (fly by wire throttle) which isn't all that common on E34/39's. It limits the power by closing the throttle regardless of where the drives foot is holding the gas pedal if the abs system detects wheelspin. It constantly compares front wheel speed to rear. (Not worth the effort not to mention $$$)
I haven't heard of many aftermarket traction control systems (proper ones using wheel speed sensors not a guestamatoin based on speed of engine rpm shift / over rev as in MSD)
Last edited by Ausmpower; 06-23-2006 at 03:28 AM.
BMW parts professional
Previous rides:
BMW
E12 M535i (go the dogleg!)
E28 M535i (MMM M88!)
E34 535i M
MAZDA:
RX7 S-IV T04 (440 hp ATW)
RX7 S-I 13b bridge port
RX4 13b peripheral port