I purchased a 03 VIII and would like to know how to tell if you have launch assist. Does this come from the factory or is it something that has to be done to the ecu? thanks for any help

 

Unless the car has been tuned you do not have the stationary rev limiter.

In 03 that was set just above the rev limiter.

 

to find out if you have it. stop the car at an intersection, and floor it. if it revs to 7600 rpm, the launch assist is not set. if it stops at 5-6k rpm range, then it is already set.

if it not set, you can get it set with a simple flash from any tuner.