hahaha, ok.....i might have been confusing everyone here including myself! doh! see how little knowledge is often dangerous!!!
okay...the racelogic system is essentially an adjustable traction control system which uses ABS.
for the traction control module, you can control how much slip you want, ie. 0%, 10%, 20% - whatever. this obviously pre-determines your over or understeer characteristics in corners.
for the launch control module, it is essentially how duncan puts it, a rev limiter which utilises its traction control logic. ie. you still need to determine what percentage of slip is the "optimum".
my bad