You've got all the good hardware in there and it's strange that you're having understeer problems. What is the body roll like? because 17mm is a pretty light swaybar.

The other thing is that camber and caster are supposed to help the turn in and reduce understeer but I'd suggest that 6 degrees is too much. It might be that case that you have so much camber that you aren't getting the car to roll enough onto the whole face of the tire. I would have thought more like 3-4 degrees of negative camber would be as far as you'd need to go.