I'm having some kind of problem with the Hyman Stadium where the doors won't open for me to get into any of the races.

I haven't used cheats on any files and none on this one. Does anyone know what the problem is?

The doors should open at 20:00 I believe.

Thanks so much, that was the problem.

Now 2 more questions:

Can Dirt Track be done in any amount of time?

and

Will the 8-Track go towards 100% even if you get 2nd place?

to get 100% you must beat/win everything, that si the case of 100%.

By Dirt track, I'm assuming you mean "Trial By Dirt". If so, then you'll be glad to know the course can be completed in any time. As for 8-Track, assuming you mean "Hotring", you're required to finish in 1st place. Both contribute to the 100% milestone.

Thanks Deo but I'm talking about the one where you're on the bike in the stadium having to collect the checkpoints like the one in San Andreas.

There's no time limit for that either. However, you are rewarded higher sums of money depending on how fast you complete it in:

$5,000 if you complete it in over 10 minutes
$10,000 if you complete it in less than 10 minutes
$50,000 if you complete it in less than 5 minutes

Those stadium events are some of my favorite things to do in the game.

There is a particular time for every event, most of the time the stadium is just gonna be closed.

the dirt track is the best, I got 4.47 minutes on that