| Which bars? Cal-Tracs or long traction bars?
Cal-Tracs - you can "dial-in" when the bumpers come in contact with the springs. So for "normal driving you can shorten the bar and it is like it isn't even there. The more "preload" you add to the bar the stiffer the rear suspension because you are moving the front mount location from the spring eye back to the point where the cal trac hits the spring. Shorter spring increases spring rate.
Just like older "ladder bars or slapper bars" where you could adjust how far below the springs the rubber bumpers ran, kind of the same idea with cal-tracs... but a much better design.
If you notice the cal-tracs hang very low on the axle end. This increases anti-squat, like what Iadho Rob was talking. "squat" pushes the rear into the ground during acceleration and "anti-squat" tries to life the rear during acceleration. Rob kept saying he wanted "anti-squat" to push the front end into the ground during acceleration, on a 4x4. However, even in 2x4 anti-squat is desirable as you want the horse power to move the vehicle forward and not be lost in chassis movement.
Drag races where 2x4 vehicles pull the fornt wheels off the ground looks cool... but is wasted energy. You don't see the pro classes pulling the front end 3-4 feet in the air???
In addition vehicle acceleration causes an increase in weight towards the rear, so counteracting that with anti-squat is sometimes required. In a 4x4 application I can see the need for a larger amount of anti-squat as Rob has stated.
Long traction bars - first they need to be long to limit the bind they put on the rear suspension (unless the have a double hinged front mount... then they basically become long Cal-trac type bars...
Draw out the rear suspension on paper. Leaf springs tend to move the axle rearward during compression (bolted solid at front end, hanger in back). If you now have a rigid bar (length doesn't change) it will either pull or push the mounting point forward or backwards during suspension movement.
This is why you try to have the bar as flat (horizontal) as possible and as long as possible. Flat because this is the angle which cause the least amount of front and reaerward movement as the bar goes up and down. Long because the long bar has less angle change between the front mounting point and axle end.
Because long traction bars bind the suspension (by design). They will cause a rougher ride depending on how much they tend to bind up. Longer and flatter reduces this tendency. A properly design set will probably not be noticed, much.
Drag racing - definitely cal-trac type bars.
Pulling - can't comment... but I hav emy opinion. I'm guessing a proper set up cal-trac type system is probably better than long traction bars. I think HUGE anti squat is needing in pulling. Why? because as the weight box transferrs it is going to push the rear end into the ground. Antisquat will try to lift the rear and put more weight on the front end.
"Cool Factor" - got to go with the long traction bars, just remember fuzzy dice were "cool" at one time too... oh wait most are probably too young to know what they are! Ok cool like Hot pink and neon green paint jobs!
So, need to figure out if you want to push the fron end into the ground or not.
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2006 LBZ CC/SB, Stock (at the moment) but looking for: 4" Exhaust, EGR block off, EDGE Evo Race CS
Last edited by lost_in_calgary : 11-09-2009 at 08:09 AM.
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