Front AND Rear Spherical Bushings?

[hardline_42]

I'll jump in here and tell you what I found during my Bad Ast research...
Leaf springs can be made to work just fine. As a road race suspension OR a street driver suspension. This is straight from Mark Stielow and his experience with Thrasher. What you don't want to do is make it too complicated which is exactly what you are doing with your design. Keep it simple. Build some height adjustablity into the front spring mounts. Run a compliant bushing in front with high durometer rears and get yourself some GOOD adjustable shocks...
Don't use sliders on a street car. All they will do is wear out quickly and cause maintenance problems.
Here is what a spring manufacturer has to say about Pivot Bushings. This is quoted from the Landrum Spring web page...
"Pivot bushings are bushings that were designed to remove the bind between the chassis and the spring. However, the negative effects of these bushings greatly outweigh their intended purpose. Our extensive testing has proven this component to produce very erratic handling characteristics. When the front bushing is allowing the front leaf spring to pivot, it transfers all the side loads and lateral forces to rear portion of the leaf spring and shackles or sliders, which were not designed to handle the additional stress. This leads to bent shackles, warped sliders and misaligned axis points. Furthermore, because the front eye is allowed to pivot, it does not have any solid displacement to drive the car forward."
Here is their site...
http://www.landrumspring.com/pages/technical.html

Leave the spring angle alone also. I looked into angling the forward mounts for Bad Ast and everything I read said to do it for turning left only... Circle track cars do this a lot. It's kind of touched on in the Landrum site and, if you look at the diagram, you will see the LEFT spring is the only one angled...
http://www.landrumspring.com/pages/technical6.html
Here are some articles to look at. Maybe you have seen them, maybe not but they are good reading and informative...
http://www.circletrack.com/techartic...h_terminology/
http://www.smithees-racetech.com.au/leafspring.html

The decision I came to was keep it simple. A street car does not need all of the race car "tricks" to handle well on the street AND on the track. Granted it will not be perfect for road racing but that is not the intended end result right? A very nice handling suspension can be built with off the shelf, easily replaced OEM or aftermarket parts.
Just something to think about.
Mark

Mark, I appreciate the info and the links. I'm now more confused than before, though. I read all of the landrum information and they seem to want to steer you away from spherical bushings and promote the use of solid bushings in the spring eyes. But most of my suspension design ideas came after reading this article (http://www.afcoracing.com/tech_pages/leaf.shtml) from AFCO who also makes leaf springs, but happen to sell both spherical bearings and sliders which they recommend (they also recommend using the spherical bushings in the front eye). They also recommend locating the front mounts further inboard of the rears. Naturally, I don't really know which piece of information to put stock in. Chicane says the best setup is solid bushings up front, pivots out back with sliders and recommends the Gulstrand FIA leafs with the Cat 5 setup. GW says the Cat 5 setup has pivots front AND rear with a solid frame bushing. Landrum says no pivots. Can anyone shed more light on the situation?