Here is my experience as of my second season of dedicated track riding... Last summer I did 10 track days, I did them consistently from the beginning of the season to the end. I started in novice obvsly and went in to it with nothing to prove and just an eagerness to learn and improve. Of my 10 days last season I believe that I did 5 or 6 of them in novice before moving up to intermediate. If you go to the same track often enough people will start to recognize you especially if you are consistently reaching out to the coaches for help and tips on your riding, the more you ask for critique and input the better. I think that patience is maybe one of the important things to go into track riding with, you see tons of guys on liter bikes who think they are fast out the gate binning it because they do not ride with in their limits. The slower you take it, I believe the quicker you will gain pace as your comfort levels will steadily increase. So after my first season I was mid pack intermediate pace with 10 solid days under belt at 3 different tracks. All days done on DOT SuperCorsa SPs, no warmers.
I want to mention something that I feel to be very important wether its riding bikes or anything else, it is super crucial to have a mentor. I was fortunate enough to befriend a fellow 959 track enthusiast who had a good solid history with cars and bikes on track and he was a fast intermediate rider at the time. Having someone to break down stuff for you between session beyond a coach is so helpful I cannot explain. From riding tech nice to tires to all the crap you have to lug around with you...Find some one that knows what they are doing.
The second season (this summer) went into very fired up. Over the winter I converted bike to full track only build, got warmers, a bigger van, and from beginning of season just been trying to do as many days on track as possible. The more seat time I got the faster I got, lap times were dropping body position started improving. I started running race compound SC dots and then quickly moved onto slicks. I am up to 14 days this summer (still counting, NJMP this Sunday), running expert pace (still in intermediate mind you) and having a blast. The group you are in doesn't matter, its all about the seat time and the incremental gains.
Just wanted to give you a snap shot of my experience after 24 track days. If you dedicate its possible to get decent pace in a couple seasons. My advice is no ego and get ready to really drop some money...