What are your toe settings?
Band-aids:
- if you have toe out, less aggressive toe (toe-in or neutral toe)
- run non-directional tires - seems directional tires tend to follow the grooves of the road and make bumpsteer worse, just observation - I may be wrong
- raise the car
- soften the suspension dampening
- increasing positive caster may help
The only "true" way to fix bump steer issues is to get an aftermarket outer tie rod, such as the kazama one.
Let's you adjust the tie rod to be relative to the steering rack so that it moves correctly when you hit a dip/bump.
