Setup questions

[Benjab]

Hey! My friend and i made a tiny track at a school. And we are using my mad rat and his b4. Its really alot of fun! Ive never driven on a track. I added 30g weight on the serve because its understeering. Its still understeering but it also nose diving more compared to the b4. What can i do to prevent understeering and nose diving?

The jump is really small and there is only tight turns.

Ive seen on most b4's in Denmark are using staggered rib front tiress. What surface arw they good for?