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Since I have this setup for my rear LCAs, when I install the sway bar, will it "hug" the "hogs head", or will the steeper angle cause there to be a gap between the sway bar and the hogs head?
Also, this is a quote from Joe to one of my previous threads:
"The aftermarket arms on the OP's car look like the old Southside Machine lower rear arms. I also have a set of these. They are designed to lower the rear mounting point at the axle to improve off-the-line traction at the drag strip. The two holes in each arm will accept the factory style rear sway bar. These are aftermarket arms. The CSM is irrelevant. Whether or not this car originally had FE2 is also irrelevant since the factory-installed lower control arms are long gone".
How does lowering the mounting point improve off the line traction?
Since I have this setup for my rear LCAs, when I install the sway bar, will it "hug" the "hogs head", or will the steeper angle cause there to be a gap between the sway bar and the hogs head? I am gonna go out on a limb here. Is this "hogs head" the rear axle center section ? In the olds days in my part of the country it was called the "banjo housing" or "banjo". I would say, from the picture, that the sway bar may not contact the rear end center section.
Also, this is a quote from Joe to one of my previous threads:
"The aftermarket arms on the OP's car look like the old Southside Machine lower rear arms. I also have a set of these. They are designed to lower the rear mounting point at the axle to improve off-the-line traction at the drag strip. The two holes in each arm will accept the factory style rear sway bar. These are aftermarket arms. The CSM is irrelevant. Whether or not this car originally had FE2 is also irrelevant since the factory-installed lower control arms are long gone".
How does lowering the mounting point improve off the line traction?
Thanks, Dave
While I am still out on the limb............ it would decrease the leverage to decrease the rotation of the axle housing. Thats assuming you had enough traction to cause the rear axle to rotate. If the axle housing rotated, it was power/motion lost on the starting line that was not transmitted to the tires. There could be a whole engineering dissertation on this subject...........ladder bars, slap bars, pinion snubbers, solid brass control arm bushings etc.
........Just my two cents worth.
Mr. Gasket offered "no-hop" bars that raised the upper control arm mount at the differential housing to change the instant center in a similar way. With the stock geometry, especially if the car is not low because the coil springs are too long, the instant center is too far forward, or there might not even be a point of theoretical intersection from the top arm to the bottom arm.
Just remember that increasing the anti-squat geometry of the rear suspension by using bars like this improves drag strip launch but hurts on-road handling. Everything is a tradeoff.
Just remember that increasing the anti-squat geometry of the rear suspension by using bars like this improves drag strip launch but hurts on-road handling. Everything is a tradeoff.
I have those SSM LCAs w/ a sway bar on mine. Note that the sway bar holes in these bars are "tilted" such that the sway bar ends up about the same distance from the rear axle differential housing (pumpkin / hogs head?) as with the factory LCAs. As Joe stated, the sway bar acts to resist the LCAs from going in different directions, reducing body roll in the corners. By moving the instant center of the rear suspension rearward, the SSM LCAs increase the amount of downward force generated by the rear axle reaction torque. X torque over a shorter radius generates more force downward on the rear tires.
Last edited by JohnnyBs68S; Apr 12, 2020 at 05:25 PM.
It doesn’t always hurt handling. Whether it helps, hurts, or has negligle affect on a car’s cornering capability is vehicle and setup specific. Many cars, such as the S197 Mustang benefits from using LCA relocation brackets to change rear LCA geometry and increase anti-squat in road racing applications.
Lowering the axle side of the rear lower control arm (LCA) increases anti-squat. But, this change in geometry can also induce unacceptable roll center oversteer. Roll center oversteer is the rear end literally adding steering angle via the rear axle.
In this instance, the LCA is pointed at a downward agle toward the axle. As the loaded / outside control arm swings up, it pushes the axle towards the rear of the car. The unloaded / inside LCA swings down which in turn pulls that side of the axle towards the front of the car. So, now the axle is crabbed in a way that generates oversteer. And, it’s not consistent. The harder you corner, the more the suspension compresses, and you get more and more roll center oversteer.
I am not in anyway saying if it would help or hurt an A-body’s cornering capability. I’ve not installed, tested, or raced an A-body with LCA brackets. I did forget to mention that LCA brackets accomplish the same thing as the SSM LCAs mentioned above.
My gut tells me that at stock rear suspension heights, you would likely induce unwanted roll center oversteer. My Olds is lowered 1.5” - 2” in the rear and the LCAs still have a slight downward angle and positive anti-squat. I suspect using LCAs at stock height would introduce LCA angles that hurt cornering capability.
Last edited by 70Rocket; Apr 13, 2020 at 06:31 PM.
