How to enter the Brighton Speed Trials with a National A Licence
This is a much shorter section than the National B one because you guys have sprinted or raced and you know what you are doing. Like any Sprint or Race, you'll be in classes. You will be in smaller groups, against more serious machinery, but machinery that is closest to your own.
More importantly, you will get one more run; those in the handicap get one practice run and one timed run. Those in the classes get one practice and two timed runs. While the handicap is over before lunch, the classes run well into the afternoon; its a full day instead of a half day.
You'll still need to have the right clothing and to pass scrutineering, though its worth mentioning that Sprinting is a level below Racing so the rules are less strict; your harnesses do not need to be in date, for instance. You'll still need a timing strut.
Check the Blue Book for more information, or feel free to ask.