well let's see here if it stiffens up your chassis it would prevent roll which would prevent less weight going to the outside tires would in that case would make a car tighter in your case understeer.

A good rule to go by is the more inside weight you have the looser it is going to be.

for example you are making a left hand turn and you want it to be loose (oversteer) you would add more left and vise versa