bump steer basics

[oldgold]

i have a car that is metric chassis that had a 8 inch ride height and now am moving to a different track which has a 4 inch ride height.
i lowered my car last nite to 6 inchs and notice the tierod ends go up hill to the spindle which i think will cause bump in?
will i have to lower the idler arm and pitman arm to make the steering level to the spindles to remove bump steer?

[Racer96m]

This is what you are trying to achieve. You will need a bumpsteer gauge to work through the process.

Dave

[save the racers]

If you can achieve what racer96 has posted your bumpsteer will change very little with ride height changes.Hard to do with stock parts.I don't know how you lowered your car.But just screwing the wieght jacks can throw the geometry off causeing more problems than lowering the car helps.

[racing_kid]

do rule require you to lower the car? Or is 4 the minimum ride height?

[oldgold]

do rule require you to lower the car? Or is 4 the minimum ride height? rules dont require me to run at 4 inchs but the car was at 8 so i lowered it to 6 inchs and was concerned about bump .lowering the car made the lowers level but i run metric spindle on the car and the tie rods go up hill slightly .I do have a bump steer guage and can check it to be honest i have never checked this car before.i figured if the tie rods went up hill to the spindles it would bump in .

[oldgold]

If you can achieve what racer96 has posted your bumpsteer will change very little with ride height changes.Hard to do with stock parts.I don't know how you lowered your car.But just screwing the wieght jacks can throw the geometry off causeing more problems than lowering the car helps. i just put shorter springs in the car to get the upper a-arm angle to change .as you know with stock uppers at a 8 inch ride height even with 6degrees camber the wheel still decambers in the turn.i guess i could have ran taller spindles for more upper a-arm angle.

[oldgold]

i also read that i would need to replace the center link to a DS1049? and shorter tie rods .along with bending the pitman arm and idler arm down

[oldgold]

i also read that i would need to replace the center link to a DS1049? and shorter tie rods .along with bending the pitman arm and idler arm down would this be true?

[drtrkr244]

This is what you are trying to achieve. You will need a bumpsteer gauge to work through the process.

Dave

Its a whole lot easier and cheaper to modify a stock drag length than to chase down all the other parts and then heating/beating other parts. Make your drag link like the above diagram and you want have any problems. Even on the outer tie rods, we would cut off the threads and weld on a grade 8 bolt(no head of course) to have it adjustable. Keep it covered with the stock boots.