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Author Topic:   front roll center
Dirt Full Roller

Total posts: 64
posted November 16, 2001 07:43 AM
Ok I finally have to ask. I have seen people post replys that say if you use the taller ball joints or longer spindles you will raise your roll center, and vise versa. Everything I have read in books says the opposite. From what I understand you roll center is the point where your control arms would intersect if you drew a straight line through them. Am I missing something here? I am running the taller impala spindles on my metric car to lower the roll center, is this wrong?
Also, is it possible to get the roll center too low??? any thoughts......

Dirt Freak

Total posts: 346
posted November 16, 2001 10:53 AM
that point that you are describing is the "instant center", not the roll center. To find the roll center draw a line from the instant center back to the centerline of it's respective tire's contact patch. Do this for both sides , the roll center is where these 2 new lines you have drawn intersect. Longer ball joints effectively make your spindle taller, which raises your roll center. 4 to 4.5 inches is considered good on dirt.

Buy any Steve Smith book, it will go into detail about the why's and how's of roll center and other important frontend geometry issues.
Good Luck

[This message has been edited by c21 (edited November 16, 2001).]

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