Pedigry
04-09-2025, 06:21 AM
Hey guys,
I am in the process of redoing my rack setup. Currently it's manual and I'm going to switch to power. Tired of fighting the car at slow speeds and the manual rack has a slow ratio which isn't great for spirited driving. My current rack has two problems. First, it's way to wide. The lower A-arm pivot points are 19" apart, the pivot points for the current rack is 29" apart. Obviously this is creating pretty serious bump steer (though ironically I don't feel it in the car, I don't know if it's because the car has limited suspension travel but i don't notice it and tires are wearing surprisingly even). The second problem is that the mounting point at the knuckle is under the lower A-arm connection point.
The first problem will be rectified with the new rack (I will have a rack with a 19" pivot point. But from everything I have read on steering geometry, the point at which the steering rod needs to connect to the wheel knuckle should be approximately 1/2 way up between the lower and upper control arm. Mine is literally underneath the lower control arm attachment point. I am guessing because that's the only place you can place the rack without it coming into contact with the oil pan.
My question is, with this setup, is there any way to minimize bump steer? I am afraid with the steering rod mounting point under the lower control arm mounting point I will never have correct steering geometry. The way these hot rods are set up with the suspension so low I can't imagine I am the only one running into this. Let me know if you have the same situation. Autocross guys probably have this figured out. thanks.216807
I am in the process of redoing my rack setup. Currently it's manual and I'm going to switch to power. Tired of fighting the car at slow speeds and the manual rack has a slow ratio which isn't great for spirited driving. My current rack has two problems. First, it's way to wide. The lower A-arm pivot points are 19" apart, the pivot points for the current rack is 29" apart. Obviously this is creating pretty serious bump steer (though ironically I don't feel it in the car, I don't know if it's because the car has limited suspension travel but i don't notice it and tires are wearing surprisingly even). The second problem is that the mounting point at the knuckle is under the lower A-arm connection point.
The first problem will be rectified with the new rack (I will have a rack with a 19" pivot point. But from everything I have read on steering geometry, the point at which the steering rod needs to connect to the wheel knuckle should be approximately 1/2 way up between the lower and upper control arm. Mine is literally underneath the lower control arm attachment point. I am guessing because that's the only place you can place the rack without it coming into contact with the oil pan.
My question is, with this setup, is there any way to minimize bump steer? I am afraid with the steering rod mounting point under the lower control arm mounting point I will never have correct steering geometry. The way these hot rods are set up with the suspension so low I can't imagine I am the only one running into this. Let me know if you have the same situation. Autocross guys probably have this figured out. thanks.216807