Please.... Do enlighten me. Since your statement suggests you know, what is it about the g-body suspension that results in bumpsteer?
Bumpsteer: Correcting or Hoping?
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To give the short hand version, a difference in angle between the lower control arm angle and the tie rod angle.
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If your tie rod ends are parallel to the lower control arm the bump steer should be minimal.
I'm under the understanding B body spindles or extremely lowered or raised setups make the generally ok stock geometry worse and causes problems.
Basically the tie rod end axis of rotation at the drag link needs to be concentric to the instant center of the control arms. Because this isn't possible in many cases, if the path is generally straight with some error at the top and bottom it's ok.
I'm under the understanding B body spindles or extremely lowered or raised setups make the generally ok stock geometry worse and causes problems.
Basically the tie rod end axis of rotation at the drag link needs to be concentric to the instant center of the control arms. Because this isn't possible in many cases, if the path is generally straight with some error at the top and bottom it's ok.
Sounds right from my research....
Since the steering arm is tied to the spindle on these cars, they remain fixed in relation to the lower BJ on the outer end. Altering ride height will have impact on the inner pivot points as the height changes which can negatively impact the already present bumpsteer.
The B-body spindle helps the camber curve but negatively impacts the steering. The steering arm is longer which slows/reduces things & is lower than the g-body's making the bumpsteer issue worse than factory.
The tie-rod pivot points need to be aligned as closely as possible w/the instant center derived from the upper & lower a-arms pivot points.
I'll add:
Altering spindle height/placement in relation to the control arms impacts the IC & Roll Center.
Adding big sway bars + stiffer springs & shocks can diminish the impact of bumpsteer since it usually also minimizes the amount/range of travel.
Tire size/contact patch & alignment settings can also impact the 'feel' of bumpsteer.
In the first paragraph you mention changing ride height messing with the inner mounts, but their height is static so I'm having a hard time following there.
I'm guessing the B body spindles are a different overall height to impact camber curves? How do S10 spindles compare in that respect and steering arm height relative to lower BJ?
When the vehicle is lowered/raised as measured @ static height, the outer measuring points remain fairly static as the OD of the wheel/tire assembly set those dimensions. However, the inner mount points will change in relation to the IC as the height is altered.
B-body & 2nd GEN f-body spindles are ~9" tall. Thus the taller height helps the camber curve (w/the proper upper a-arms & alignment).
S10 spindles are the same as the g-body dimensionally. The steering arms are in the same location. The heights (even the later bolt-on hub style) are also the same.
I'm thinking bass ackwards from you. I'm basing everything around the car, so in my mind the wheel and outer pivot points are moving relative to the car. In the end, it's all calculated the same.
Never even thought about that perspective but true, either way works. I always thought you 'gotta measure from the specific points & never wondered if one was better vs. the other when shifting heights.
Have you measured the difference? I have read that before and have measured it, very long time ago. Dont shot me cause iirc I dont think there is much of a difference if any. Some time ago a buddy of mine installed b-body spindles on a 65 a-body and that was a problem, reduced turning radius. I turned down the lower balljoints so the newer spindles would fit his 65.
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