Originally Posted by
Moose32
Been to some other forums...and read many books, and everyone seems to have a diffrent take on where the roll center should be on a DIRT car. I'm thinking the RF camber gain/upper a-arm angle would be more important than actual "static".
I'm actually building a new Late Model Sportsman (with a camaro stock front clip, stock lowers and spindles). Got it up on blocks and I've got 17 degrees on the uppers... 1-3 degrees on the lowers (LF has more than RF). The roll center draws out to 5 1/4" off the ground, and 4" to the right. My upper mounts are serated, so I can move the RC left to Right fairly easily. I have 2.5 degrees of camber gain in the first 2" of travel.
I would love to hear everyone's opinion on this, and also try to see what seems to be the norm for some of these LM chassis builders (what seems to work for them)
This is a question that keeps evolving. Most everything I've read or had experience with places the RC between 3 to 5 inches high. Left to right is debatable, I know Rayburn's were up until the last couple of years more to the right than some others and the cars tended to be tight on entry, but worked well on big tracks like Eldora. The Hook setup changed the way a lot of car builders thought about the RC lateral placement. I know for a while some builders worked towards having a migrating RC that moved towards the RF, but it ended up making the cars pretty tight. I knew of one car that had the RC climb up on top of the RF tire during roll. Now I've seen more builders putting the lateral RC more left to help the cars turn better. Bottom line is every choice is a compromise, usually better driveability means less forward traction or a lose in sidebite. The latest trend is to have way shorter LS lower control arms and longer RS lower control arms.
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