First run at the track, time a guess?
It really depends on the track and tech people. Here in michigan, i went to two different tracks trying to do the same thing your doing, and really only got hassled at one of the tracks. If the timing tower is paying attention, they will be able to tell what your car is capable of by watching the launch and will soon find you if your close to 11.50. The problem really comes from not wanting to lift before the 1/4 to see what your car will really do. So make a couple passes and if your closing in on 11.50 you better get the bar. I learned the hard way.