Just keep looking at this board. Announcements are made from time to time.
You can also contact Kookie Ramirez (88 St. Martin Street -- that upward road going to Ultra). Or Louie. Sheesh... I forgot the number.
From what I know, when they do hold these events, it's P1,000 (P750 if you register at least a couple of days ahead).
You need:
1. Registration Fee
2. Car
3. Helmet
Roll cages not required.
I think you can also contact sina Kookie so you can borrow the track for a fee. I think P1,500 yata for a whole day per car (pero, any damages you do to the track, sagot mo. And damages that happen to your car, sagot mo rin. You get the picture).