Unless the University has some deal with Pearson Publishing, the company that makes the ACT, then the results re almost never immediate. A few weeks at least. That's not to say that there isn't some sort of deal in place, but usually it's an ordeal.
And don't be to sure that an 18 is a walk in the park. I wish it were. Unfortunately, the test kills some students. I am a teacher and coach and I have athletes that are 3.5 GPA in the classroom, but can't score higher that a 20 on the ACT. Because of that, I now require all of my players to take it 3 times before graduation. Studies show, the more you take it, the more you improve.