Front Roll Center

[racinlm]

I asked this question in the latemodel section, but I wonder what the opinions are from the modified group.
Messing around with some front roll center stuff and trying to understand where the trend is for roll centers and what effect they have on the car, and ultimately what types of track conditions favor the location. My application is with a dirt modified, but I come from the dirt latemodel world and I "assume" the location would apply to either application.
So my questions are:
1. Would the front roll center height vary between an aluminum motor, steel block aluminum headed motor, and an all steel engine and would setting the roll center height matter for those combinations?
2. What effect does the roll center have from left, to center, to right? I make the assumption that having the roll center to the left is going to make the RF softer and make the car lay down on the rf more and not pick up the left front as much, would that be true or false, and for what type of tracks is it best located? Left for dry slick, in the center as neutral, or where do you "think" most roll centers are being located?
3. Does having the roll center located from right to left have to work in conjunction with the caster or does it even matter, and if it does what direction would you go with the caster based upon roll center left to right location?
4. Does the spring combination matter with the roll center right to left?
5. Is there anything to the front to rear roll center location?
6. Where do you think the roll center is from right to left on most latemodels and most modifieds?

I know I can run the program or figure out where the roll centers are, I just want to understand the effects or just some ideas of how I attack the front roll center. I never gave it alot of thought because those things were figured out by chassis builders, but I find myself wondering...
Thanks,
Chris

[95shaw]

For a mod, no bump stops, changes to the rf upper ball joint stiffens or softens the rf spiing required to achieve the desired travel.

Might be easier to think this way, and look at camber at the desired travel.

Lf upper ball joint changes the camber curve here also.
In the advent of tie down shocks and tethers/ short lf shocks, how much travel are you getting?
Most important should be cambers and contact patch loads at the location chassis spends most of it's time.

The four black round things, and how they interact with the track, are the most important thing.
How we arrive there is mostly window dressing.