I have noticed that whenever I do a datalog (HPTuners), 99% of the time, my injector duty cycle will be higher, just goofing off on the street, doing rolling burnouts, than it is on the dragstrip, in an actual race...

Higher, like 10-15% higher...I may hit 75-80% on a 16# boost run, but may hit 95% playing around...
Maybe 40% doing a burnout in the burnout box though, with no load, obviously.

Is that normal?

 

You would have to post the logs, but tip in fueling is going to require more from an injector than sustained increase in load. With the initial rev in like a burnout, where you are commanding max power: revs are coming in very quickly so you need max tip in enrichment, Your transient fueling will also be maxed out because the beginning of the burnout is going to be low velocity air flow in the manifold and your rapidly increasing air velocity the entire time. The burnout should, at least in my brain be the time where your commanding the most fuel. All these demands are lessened when you have traction and you slow the engines rate of acceleration down.