You're right, bumpsteer can never be eliminated, but why make it worse if you don't have to?
This is not correct. The main problem with the stock suspension design is it places the roll center of the front end under ground. The roll center is the point in space around which the mass of the car pivots when rolling, as in a turn. The further away from the car's center of gravity the roll center is, the more body movement you get in roll. This causes the mass to move further, much like the difference between a pendulum with a short and vs. a long arm.
The camber curve is a function of control arm length and initial ride height, but it isn't the main benefit. Using a taller spindle like the AFX, B-Body, or taller ball joints with the stock spindle moves the roll center. In the case of tall upper ball joints, it pulls it up from about 6" below ground to about 1" above. The AFX setup is even taller and literally pulls the front roll center up to the center of the crossmember right below the engine.
To demonstrate the effect, go pick up a 25lb dumbell. Hold it in your hand straight out in front of you, and try to wave it around. Then pull it up against your chest and move it the same way. One way is much easier than the other.
The effect on the car is dramatic. The car responds much quicker to inputs and doesn't work the tires as hard because you aren't wasting energy trying to roll the car all over the place when you change direction. Steering feel and responsiveness improves. It also lets you get away with a smaller swaybar and allows mounting of C5 and even C6 brake rotors and calipers. Your front tires will actually run cooler and last longer when driving like a maniac because you aren't working them as hard.
Again, the camber curve is a function of control arm length and ride height (as in, where the spindle is in relation to the car at rest, not necessarily the ground). What size wheel and tire you put on it doesn't matter much. Tire diameter WILL alter toe.
I don't think the B-body spindles are a good move anymore. They had their day, but they introduce a lot of bumpsteer, really hurt the cars turning radius, and eff up the ackerman which will cause goofy tire scrubbing in tight turn situations.
As for the OP's question about brakes for stock spindles, you can buy factory new Blazer spindle/hub assemblies and get those 11" brakes, or you can have a machine shop lathe the rotor off a set of stock rotor/hub assemblies, cut off the stock caliper mount ears and make a mount bracket for the Blazer calipers out of plate steel.
Another option is the Wilwood HD front brake setup for our cars. It's still a 10.75" rotor, but it's a much thicker rotor with an aluminium hub and four piston calipers. It's a huge step up from stock and still fits behind the stock wheels. Baer also has a large rotor front setup, but it's twice the price of the Wilwood kit.
I was going to give a really long explanation but to be honest it's will more benificial to post info so that other can do the math themselves rather than rely on someon else to figure it out for them. Here are a few links that I think members might find interesting and I'm also posting the calculation for figuring bumpsteer and camber change. This may be overly complicated for some but it will provide the best explanation for someone that is willing to do the work.
Ackermann steering geometry - Wikipedia, the free encyclopedia
Bump steer - Wikipedia, the free encyclopedia
Camber Change - Static & Dynamic - Tire Traction - Tech - Circle Track
OptimumK Help
This one may confuse you some but it's a lot more of an advanced engineering board and I doubt that many here would be members.
I
am however. LOL
Automotive suspension engineering - ISO8855 toe and camber angle definition into rotation matrix form
Automotive suspension engineering - Yaw damping
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Vehicle Dynamics, SLA Suspension camber change and bump steer example 5/11/09
Determining Camber angle and bump steer
Setup all the suspension points in space, with origin at upper pivot. P2=(0,0)
Determine coordinates of remainder of points as
a. P0=(-1,-9)
b. P1=endpoint of lower A-arm, (10,-9)
c. P3=Endpoint upper A-arm, to be calculated, (10,1)
d. P4=Origin of tierod, (-0.5,-4)
e. P5 = Endpoint of tierod, (10,-4)
Calculate R1=|P3-P1| and R1 = |P3-P2|
Set up equations for C,D,E,X3,Y3
Calculate X3,Y3 for initial positions and determine signs
Increment q for +- 10 degrees and calculate P3
Calculate camber change, body roll, and net camber change
Setup Chase 2C using P1 and P4 to determine P5
Calculate P5 optimal from P1 & R15 using spindle angle calculated above
Bump steer is determined by the difference between optimal and actual P5 DIVIDED by the ratio of tie-rod-arm length to wheel radius
Show that
DWF +DWR = DW = Zcg/t*Fy in all cases.
Define each of the terms in the above equation and discuss the limiting cases for each, .i.e. when do terms collapse and what do they mean?
Derive the relationship w = 188/x ½
Calculation of roll Gradient
Swaybar: 24.8mm F, 23.5mm R, Calculate roll rate example
