G'day rccardr,
It would be interesting to see some of your setups.
We have found that with light mini's we tend to roll over very quickly.
For our local mini rules we have to be above 1330 gms to be legal. We have found the MO3 to require the extra weight to be stable and the MO5 needs to have weight added to become legal weight.
Perhaps I should do some more testing, however we did see yesterday that our normally fast driver left the extra weight out of his MO3 and he traction rolled and was slower than normal. When he added weight to his car, he was the car to catch.
Regards,
Calvin.