Chad, it's really simple at cc. Read their rules before you post, and follow them. The issues everyone complains about there is "how they treat the newbs," and how rude they are. To some there, it IS a bit of a game, there is a lot of internet bravado that I am certain wouldn't be present if was face to face, but so be it: that's the sign of the times. When you post, be specific, give details, and ask specific non-open ended questions. Once you get a bit of earned respect there, you can ask about anything and not have to worry. Don't expect them to design it for you, they won't and it's clear that you aren't looking for that. Small, specific questions.
Now, to your thoughts. Scrub radius is very important, too much, and you will generally chew up your steering gear, especially with wide, sticky tires. Too little, and you lose steering feedback. I'd suggest somewhere between an inch or two, no less than an inch. Look at it dyncamically too, make sure it doesn't go "positive" then "negative" in practice (which will be unlikely if you keep it over/around an inch or so). BUT, since you are already looking at scrub radius, you have already selected your spindle, which I think you noted is the MII unit. Ditch it. If you are starting fresh, start with the spindle, it's the hardest damn thing to find for the setups, and unless you are REALLY good at fabrication and engineering stress analysis, use one that's already made, this is a CRITICAL component. MII's have been used for decades now, originally because you could use a rack with the setup pretty easily. The MII spindle of today is the "C5" Corvette piece, and just like the MII, it can be used, but both require compromises, some may say minor, I say that they are major. When you try to get it "all" in a front SLA, WITH a typical V8 engine IN a typical muscle car/truck, you find that packaging the engine relative to the rack and pinion unit is a complete PITA. So much so, that for us, with our forthcoming "Extreme" suspension systems, we are designing and fabricating our own spindle. It ain't cheap, but if you're going to do something, do it right. Anyway, you might be forced to compromise scrub radius if you want to acheive a certain "look" with the wheel selection, which often times is really important. The AFX spindle (or rather, the completely bitchin' AFX spindle) was designed as a bolt in upgrade for the first gen F body cars, and as such, expect the scrub radius of that piece, as applied to that situation (which is very similar to yours in terms of track width) to the same as a stock F-body car. It is a very nice piece, and it may, or may not fit into your build, that's all on your shoulders.
The lateral migration numbers you noted, show you pretty clearly how darned sensitive all of this stuff is. Again, you are going to have to pick your battles, but this is where the design really takes form. You can make it such that the roll conter moves laterally less than an inch, it's really not a problem. If that's the main concern, it can be done. I had a former employee that was obssessed with this, and while it is cool in itself, if you aren't looking at the rest of the picture, it can be misleading as to how good the design truly is. And you are right, roll center height, camber gain, roll center migration, all of that stuff is related. Without question, excessive camber gain will kill you in very hard braking, espceially if run some static negative camber to begin with (this is a general statement, by the way). So yes, the approximate gain of between 0.6 to 0.8 or so per inch "seems" to be the best range when all things are considered.
Two more points on this. One, when do you really need camber gain? In roll? Pure roll? Or do you need it when you're turning? Point two, what's the inside tire doing during all of this? Yes, in a hard turn, weight transfer happens, so there is less loading, but that doesn't mean you can ignore it!?
Fun eh? Oh, and it's all just begining still, wait 'til you move on to the steering....
Mark
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