Further Front Caster Comments/Questions
FORUM Thread: Front Suspension Mod’s for Discussion
Will be receiving the Moog CC655 springs Fri-Mon. Also intend (hope?) to improve caster range (now have a max. of one degree, by adding another one-and-one half degree w/ the following mod. in order to improve straight line stability for street use. Looking for suggestions/evaluations of the mod’s.
Will elongate the X-member mount’g holes for the upper and lower inner ‘A’ arms. Then, will use offset ‘shims’ that I fab’d - they provide a slight lift to the front of the top arm and a slight drop to the rear of the lower arm (approx. 3/16” and 1/8” respectively). The shims also have a projection on the bottom, next to the mount’g hole, that will act as a spacer/locator into the elongated holes (and help prevent fore-aft movement).
A full size side view layout was made on graph paper of the top and bottom inner arm bushing mount points w/ the axle C/L superimposed over it. Then a clear Lucite sheet placed over it and the points traced to the overlay. The plastic overlay was then rotated one-and-one half degrees to determine the shim thickness and length of the offset mount’g hole (approx 3/16” top and approx 1/8” 2 bottom). Due to the axle being lower than midway between the upper and lower bushings, the top holes would have had to move rearward more than a ¼’, getting into the curved part of the x-member mount area. As a compromise, the point of rotation was moved up from the axle C/L to a point slightly less than half way between the upper/lower bushings. The result is that the axle C/L is moved forward approx 1/8 – 3/16”, with the top hole location slightly more than 3/16” and the lower slightly less than 3/16”. It is a sacrifice to true/correct suspension theory – However, there is I believe, more movement allowed by the front rubber bushings and rear leaf springs.
Any comments are appreciated – I would rather make corrections now rather than after the changes have been installed.
(regret that drawings are not included – I use the local library’s internet system and have not yet found a way past its security system)
On one hand, you’ve got the basic idea on what you need to do to achieve the desired change.
On the other hand, this is a lot of work for very little change. Why do you think you need 1-1/2 additional degrees of caster ?
I’ve had my ol Lark up to an indicated 110+ (and my speedometer is fairly accurate) with no ill effects.
If you plan on going faster (140 +) in a straight line (like Bonneville or the like), you should be heading up to 5 or 6 degrees of positive caster, not 2-1/2 degrees. And to do this….you’ll need “really” big slots…! And I doubt that with the angle of the lower control arm….it would be slowing you down from dragging the ground..!
Not making fun…just a comment..
Some of these front suspension changes are just a lot of work for little gain while using the Stude suspension. Adding a longer king pin, dropping the control arm attachment point isn’t too big a deal. Trying to change the stock parts to a high degree like this….in some areas…just isn’t worth the effort….to me.
If you want a bunch of caster…wait and see what Len comes up with. It might just be easier to adapt ball-joint type control arm/spindle to the Stude chassis and have a fully adjustable assembly.
I adapted a C4, Vette suspension to my 60 Lark chassis. Though the car isn’t complete, I’m very happy with outcome. I’m positive it will do exactly what I want it to do, and with much adjustability to adjust it. But…it was a full parts swap.
Thanks for the comments.
The springs will be changed at the same time, the shims are already fab'd, so the extra labor involved is minimal. The reason for pursuing the caster change is the result of several comments made by chassis people and the opinion of an "old Line" alignment guy (2 nd generation) regarding the desirability of 2 - 2 1/2 degrees for stability at road speed (70 - 80 mph) - as a separate progect, yes it would be a lot of extra work.
I am unaware of Len's ball joint project - I'll see if something can be found w/ a search.
Paul, Len A.K.A. Skybolt, just letting you know we have a project in the works, will take more time than your mod to finish as it appears you are about to put metal to metal, or have done already.
Here is the link to the forum thread Mike mentioned. You would have gotten more responses by just adding to the rest of that thread. It is the most actively viewed thread on the forum. So I will copy your comments and post them over there so there can be a continuity in purpose. All things that can be done with the Studebaker front suspension, the why and why not. I'm not trying to hijack your thread but want to make sure it is included in the thoughts of all who might have any comments.
Paul, You were one of the first to post on the other thread.
If you have a problem with what I have just done, sorry, but I want to try and collect all the thoughts and efforts I can into one place. Although the racing site has a similar thread about suspension mods but that is also linked to the thread on this forum about suspension mods. Please come over to the other thread and add some comments as you are, in fact, doing something others have thought about and some have tried somewhat similar mods. Any thought about what we are doing will be appreciated, Len.
Last edited by Skybolt; 08-18-2012 at 04:07 PM.
Paul, what you are suggesting will work and work well. I did essentially the same on my custom Hawk project. It's the easy, inexpensive way to get more positive caster.
What it does not do is what mike and skybolt are working toward and that is reducing outside front tire camber gain when the body leans in corners. I used all the available Stude adjustment and then controlled body lean with heavy duty front sway bar and stiffer rear springs. Again, the CASO way to get close without welding.
Agree with all the above - Yes, thanks for forwarding the info to the previous thread. Yes, the camber change is NOT addressed - I'll leave that for another time (the Stude' is spending too much time lately on jack stands - Needs to earn its keep, although I do enjoy working on these changes immensly).
Looking forward to where the original thread leads - Many heads are better at working things out.
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