First run at the track, time a guess?
Tell them it's the first time out and they'll let you run. Make a run faster than 11.5 and you're done. If you think it might turn a best of low 11's, you'll probably have to make a number of runs to get there.
If you actually DO run low 11's, you ought to put a cage in it anyway. If you don't want to put a cage in your car... um.. build a slower car...? Or, don't race it.