Post by
Q45tech »
https://forums.nicoclub.com/q45tech-u112.html
Wed Sep 11, 2002 12:07 pm
It would be great if someone had a set of racing weight scales so we could get an exact graph of the TOTAL spring roll rate vs inches of the front and rear suspension.
As we know the spring rate but not the added spring rate of the nitrogen in the shock [pushes up wards just a little] plus the spring may be a little non linear in captivity], plus the rubber strut tower doughnut, then the offset from the tires center, plus the exact stiffness of a 28 mm bar mounted in rubber with the bushing end links.
My calculations are good but still prone to errors that creap in and at best I am only 90% correct whereas a race car is know to the pound not 30 pounds [or more] of potential error as I might be off on the front in roll stiffness per inch......120 pounds is significant in a 4" body roll you might be compressed against the bump stops in just trying to get another 0.02G out of our behomoths. As the max for the tire is 1521 so 120 pound variance is almost 8% which could translate into a 5- 8-11% variance in the possible G force ability of the front tire which is the limiting factor in the slalom.Why I like 1640 tires [on the front] they can handle my possible errors better with their added weight carrying capacity.
There is a method to my madness!
See if your front end bar link bushings are worn even 1/4" [1/8" on each of the two x both sides the front bar loses most effect for the first 2" of body roll so the total front stiffness is reduced by 300+ pounds allowing the body to roll an 1" more than we portray.
Just wait you'll get to the point where as you tighten the rear the front moves more, as you tighten the front the rear moves more....finding the Goldilocks adjustment is a constantly changing battle......quarter of a turn on a nut [compressing bushings] get noticeable. And they change with bushing, tire, and shock temperature............tire pressure variances of 3 psi begin to be noticable.......they say a Nascar driver can feel 1 psi change!