So are you having this slip clutch slip issue when you see this slipping car light come?
The VDC coming on is something you could mistake for clutch slipage if you didn't know. I only turn vdc off when I'm racing or hooning.
As for race shifting, I usually shift around 6800 rpms. Here is a link to a racing shift point discussion on this site that you might find interesting.
redline/peak H.P/ & H.P curve-When to shift?? :) intresting???