Create a nice 35W motor, controller for 96V50A, set up some combination of batteries to 96v 40Ah and create enter at a new racing category!!
Bruno,
You may have a slight problem with your calculations, as I'm not convinced the motor is large enough.
Trying to shove
4800W through a
35W motor is just asking for trouble!
Perhaps that's why your rockets keep exploding?
AlanP.S.
What are the chances of making them street legal?
Now that really would be fun!