Miatav8,MstrASE,A&P,F wrote:
Richard, when you collect the necessary dims and put them into vsusp, post a link to the page so anybody can try to improve it.
Try a ratio of near 1.5/1 for lca/uca, 70-100 vsa, camber loss on the outside wheel of .75 per degree of roll with zero static neg camber, rc that is below the frame, doesn't vertically and doesn't move far from side to side in roll.
Any increase in neg static makes bump worse and roll better by the same amount.
This is an excellent starting point. I found with my design I ended up with around 100" virtual swing axle length, much longer than my rear setup. I opt for less camber gain with roll for the front setup, hence the longer virtual swing axle length, since both bump and caster add a good amount of camber. My rear suspension gravitates towards better roll compensation (with a bit of excess camber under bump) so that the outside tire is at 0° camber with 4° of body roll. Add 1" of bump (some bump under roll is expected) and I have about -1° of rear camber while cornering- just about ideal when slip angle is taken into account.
The front end, on the other hand, has slightly positive camber when purely in roll- about 1° at 4° of roll. Add the effects of caster angle and some 1" of bump and it turns into -1° in an actual corner. These are all approximate values obtained from susprog3d- but the goal is simply to have the front have slightly less camber than the rear at all times in a corner, and less camber gain on bump than the rear. This will tend to make the car understeer at the limit. Static camber is then adjusted after camber gain with bump and roll is figured out, but -2° of static camber in the front is a good starting point.
As others have said- its all a compromise. software like Susprog3D or wishbone or others can really help nail the design, but in the real world it won't be perfect. Still- it's useful for quickly seeing what changes to design do and to have the software make small changes in positioning in order to reduce your roll center migration is great to help find an initial starting point. Chances are, unless if its wayyy off, you will be happy and some minor changes to static camber /caster angle will be all you need once the car is built.