More details,
You are not required to sign up for N group your first time there. My first 20 dates there I rode I and A. It wasn't until recently, I rode the N group.
On a stock 250, your gunna bottom out the stock forks with super hard braking for turn 7 and turn 1. If your fast, your gonna get some frame flex on a few other corners.
Do NOT charge corners at this track. The keyhole and carousel are tricky corners and will not reward you by charging them. If a rider runs off turn 7 at pace, expect to catch some air on the way to china beach. On 600cc+, turn 10a is a short shift corner and turn 11 is pinned but your front will get light.
If you're ever in doubt, short shift! The blind crests on this track are crazy fun but take some time to work out the lines.