Car is 94 Accord lowered on Koni yellows with H&R sports. Has been that way for a few months and several autocross events. I only started noticing the problem this week.

When turning the steering wheel right, at about 1/4 turn there is a soft thunk and the steering feels like it slips fractionally farther to the right. When returning to center steering, the steering makes the same thunk and slips a little left. No noise or slip when turning from center to the left or back. No clicking at all in either direction. Only seems to happen at low speed (though I might just not be able to notice at regular speeds). And only at 1/4 turn.

Any ideas?

 

You may have a loose nut on the radius arm. All you have to do is tighten it up, and you should be fine.