No you don't actually "set" the timing but you can trick the computer and advance the timing by moving the CAS. I don't know the specifics but there is a good write up on twinturbo.net

 

Actually....by rotating the CAS you are setting what is called the "base" timing which is 15 degrees +or- 2 degrees.. The ECU makes adjustments from there(like a vacuum advance)....so if your base timing is off, your car will either be sluggish( timing below 12 deg.) / or you will likely detonate (anything over 18 deg). If it has never been checked it is a good idea to take a look. Loosening the three bolts on the cas and rotating it very slowly will either advance or retard your base timing.

All you need to be sure of when you check/set the timing is that the car is at full operating temp, and that all accessories are off(a/c,lights,radio...anything that drains significant current)

Hope that helps....