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Author Topic:   Lift bar Question
showtime13
Dirt Full Roller

Total posts: 60
posted February 08, 2005 03:05 PM  
When the track gets dry and slick do u guys tighten or loosen the fifth coil? We use a 250lb. spring with about a 1/2inch preload.

rocket36
Dirt Freak

Total posts: 209
posted February 09, 2005 01:45 AM  
we never adjust the amount of pre-load from the standard rocket setting of 1/4".
you could maybe try lengthening the effective arm length (coil over location) to 38"max. if your not already there. We normally run 36" with 300 or 350lb spring.

[This message has been edited by rocket36 (edited February 09, 2005).]

showtime13
Dirt Full Roller

Total posts: 60
posted February 09, 2005 02:13 PM  
Would a stiffer spring help give me more traction?..not sure about the length. Do you measure that from center of rear end to center of fifth coil?

rocket36
Dirt Freak

Total posts: 209
posted February 10, 2005 12:16 AM  
a stiffer spring will only give you more instant traction, if there is some to be had.
most likely a softer spring or maybe a variable rate spring would be better for extremely dry slick tracks.
the lift arm length is taken from the axle centreline to the centre of the coil over mount on the arm.
our arm has holes in 2" increments from 34" to 42" and we have our 6th coil in the front (42") hole.

don't forget that the lift arm is there to try and maximise traction by lifting the cars weight (centre of gravity) and the spring is there to cusion the shock loading (reaction force) of the tires trying to grip the track surface.

[This message has been edited by rocket36 (edited February 10, 2005).]

ausracer
Dirt Roller

Total posts: 5
posted March 11, 2005 02:20 AM  
we run 1/4 mile tracks and always adjust the fifth coil during the night. we run a 250lbs spring on a 32in arm with a straight 3 shock on the left side of the diff. we start the night with 1/4in preload early in the night and tighten the car by putting on about 4 turns per race down on the coil. try it,it definently works.

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