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Author Topic:   Is there a formula for 5th arms?
posted July 31, 2000 08:33 PM
Is there a formula to use in figuring out how long to make a 5th arm and how far away from the rearend to mount the spring. how much arm travel is to much? 3 inches or is it based on getting pinion angle to zero? my car enters fine will pull through the middle but doesnt have enough forward bite comming off no matter how you exit (ie. straight, hungout, softpedal, roastem ) needs just a little more forward bite to be super quick. Im open for opinions>

posted August 02, 2000 06:49 PM
Typically you'll want the spring mounted farther away from the rearend on a dry slick track and closer for tacky.

The 5th arm on our car is 36" from the center of the rearend and works really well on dry slick. We get about 3-1/2-4" of travel with a 225# spring.

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