Cambered solid rearend

[Damn True]

IC = Instant Center

[Norm Peterson]

It still rotates about its side view IC, though perhaps not a whole lot. Then again, there isn't a whole lot of difference between a 50" side view virtual swing arm and a 50" real swing arm (with a physical arm and pivot) . . .

Norm

[RobM]

with sour suspension having not much more then 3-4 inches of travel max, i cant see the toe changing a noticable amount

[wendell]

rat,

TLWiltman did a pretty good of explaining the relationship between rear camber and toe. To recap...

With the pinion angle at 0 and 1 degree of negative camber,the top of the tire is pointing towards the center line of the car in the verticle plane. If the pinion angle is at 90 degrees the pinion is pointing straight up your 1 degree of camber is now 1 degree of toe out(the rear edge of the tire is pointing at the center line of the car in the horizontal plane). If the pinion is further rotated to 180 degrees (pinion pointing at the rear of the car) your degree of negative camber is now 1 degree of posstive camber.

Because your truck arm rigidly mounts the axel, pinion angle will change as the suspension moves the axel up and down. Any change in pinion anlge will correspond to a change in the camber /toe relationship. Hope that helps.
edit: three new posts by the time I was finished

[TLWiltman]

Basically, if you have 0 toe at 0 pinion angle, and then add some negative pinion angle you should be perfectly OK. The big thing is that you NEVER have toe out. Also, with a T/A rear suspension, the pinion will rotate upwards a bit under acceleration due to the rubber bushings at the front.

[trackrat79]

I don't have rubber bushings in the trailing arms. With the length of the arms the dagree change from travel is about 15-20. Is that really enough for me to be worried about toe out and what would you recomend I have the pinion angle set at to minimize that possability. Given a 1 dagree camber set for each wheel.

[RobM]

are you running solid bushings or just somthing harder then rubber? im building a rear suspension and im trying to decide what to do with that.

[TLWiltman]

are you running solid bushings or just somthing harder then rubber? im building a rear suspension and im trying to decide what to do with that.

Options for truck-arm mounts...
-Rubber
-Speedthane-compounds range from hard to soft. Often used for tuning by NASCAR teams.
-monoballs

Pinion angle. If your 1 degree camber is at 0 pinion angle, I would think... -3 to -4* pinion angle should work. With monoballs, you might be able to reduce that to 2-3*

[cagedruss]

I would not suggest it. Puts abnormal wear and force on the factory Axle bearings. Generally we use about 1-2 degrees neg. Camber on the axle tubes. But we are using floater housings with a rather large wheel bearing and they are easier to inspect and change.

[Norm Peterson]

More than 1° and you do need to do things a bit differently.

But I'd rather have about -0.75° than zero, and absolutely do not want to see any static positive camber back there. Having it go slightly positive dynamically due to axle roll means that you're already giving up some grip on the end that you have no direct control over - with this occurring at the time you need all the grip you can find.


Norm