'71 Camaro Control Arm Redesign

[searly71]

You're right, I'm not going to gain a whole lot by replacing the arms. I don't expect any major changes in the handling. I'm just doing this because it's a fun car-related project and a good exercise in suspension design, CAD, FEA (finite element analysis--for stress), and manufacturing techniques.

And while I'm a newbie and suspension is probably the vehicle system I know the least about, there CAN be dynamic changes in caster. What you measure when you do an alignment is the unloaded caster--there are no loads other than weight and the reactions to this. If you could measure the caster while the car was turning a corner and pulling 1g, it would be different than what you measure during your alignments. If you don't believe me, download Perf. Trend's Susp. Analyzer demo (http://www.performancetrends.com/SuspAnzr.htm). Open up any vehicle (like the '01 vette), look at the static caster, input a roll, dive, or steering change, then look at the dynamic caster. This program even calculates the change for you. Look at the 'side view' to see the change visually.

As for the camber change, you're right, it should gain negative during bump. When I was talking about positive gain, I meant during turning (on a flat track, like a skidpad). A well-designed suspension will maintain almost 0 camber during turning, so that the tire's contact patch and traction is maximized.

As for the camber, I can just change the length of the upper arm, which relocates the upper ball joint. That's the same thing you're doing when you add or remove shims.

As for roll center migration, I'm still looking into that. I based those statements on what I read in Herb Adams' "Chassis Engineering". I'm not an expert, but he is.