hey,
I'll "attempt" to answer this.....
when you lower your car there are a few things in your steering and suspension geometry that change...
one is your front camber,this can cause the wheels to pivot on the outer edges when you turn in the 80% area...thus giving you a floating effect from the steering wheel,and in my case at this point the steering wheels now pulls its self round!!....this is also affected by size and type of tire used....
secondly,your steering arms will now be toeing in or out,if you have not had it corrected....this also causes the car to "track" due to geometry changes as you go over ups and downsin the road,and will also effect the way the car acts under full lock...
and check your lower arm bushes,and nuckle joints for wear..
Regards
Paul