Trailing arm pivot angle

[PATCO]

What is the best rear trailing arm pivot angle (buggy) ? I've seen some sand cars with 0 deg .How would a car handle with no camber change? Car will be play/sand with dual pivot arms . Fabricator, Bob Sheaves, I would love to hear one of those great super technical answers.

Thanks, PATCO

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[vwguy]

pat the angle of the trailing arm wont really effect anything that much.

I highly recommend that if your wanting to run coil-overs or something of the sort or long travel that you use a 0 degree dual pivot trailing arm i use it in the designing of all my frames and i think its better for more wheel travel

if your going to run something more mild i would say it doesnt matter about the pivot angles

above all remember that the camber change would not effect the riding of the vehicle and the use of it off road and the camber change could also help a little with cv joint angle a little (just thought of that)

[FABRICATOR]

PATCO
What do you mean by dual pivot arms? Is this a VW type system?

[PATCO]

Fabricator,

What I'm talking about is a vw style rear trailing arm using something besides a torsion bar such as a coilover or airshock. The same as what is used on a 1 or 10 car. Sorry if the question was not clear.

PATCO

[vwguy]

now that i know what this for i highly recomend the 0 degree dual pivot arms because there is no camber change and the long travel use

[FABRICATOR]

PATCO
Rear geometry is usually not very critical in the sand. The VW rear suspension has good geometry above straight out, or zero camber. But it has poor geometry below straight out. Negative camber is very beneficial on the outside wheel during cornering. It increases traction and reduces tire deflection or squirm. Positive camber is, generally, never desirable. On an outside wheel, it reduces traction and increases tire "squirm." On a vehicle equipped with single control arms, such as a VW, it can cause he chassis to be “jacked up” and contribute to a roll over. An inside wheel in this condition can also contribute to a roll over. The reduced stability of the vehicle with both wheels being at positive camber is compounded by the track width becoming much narrower.

A zero camber change setup should work fine in the sand. VWGUY is right in stating that it should not affect the ride much. Handling will depend on wheel travel used and speed (doesn’t everything!) Straight line traction should be very good. The travel must be kept short as this is not user friendly to the CV joints. Zero camber change equals a lot of CV plunge. This should be considered in a high horse power application. CV joint plunge can be reduced by axles that are “swept back” at an angle. Long travel applications must do this.

There is the option of a single trailing arm with two outward radius arms (like a lot of street cars). This can be setup to provide negative camber in both up and down wheel positions. Although this causes a bit more CV angle at the wheel down position, it greatly reduces joint plunge. It also adds stability and works toward maintaining track width. The increased joint angle is generally tolerable as traction is poor at this point. This would be good for handling, ride and CV joints.

It’s kind of hard to relate to short travel suspension. Hope this helps.

[vwguy]

well for the info porsche 930 cv joints have angularity up to 26 degrees and handle up to 600 horsepower that is the only joint that can be used for long travel besides another porsche joint but that one will work fine and i correct my self in saying that it wil not efect ride at all considering that is all in your shocks and coils

[DEZFAN]

This thread was started a while ago, I would like to add something though. What if you tilted the trailing arms in, as in tilting the pivots down toward the center of the car to gain negative camber. Other than possibly over extending the axle and outer cv, what are your opinions on this?