Is this the suspension with 4 mounting points on the body, two with just a normal longitudinal rod, under the axle, and two in a V shape to a single point on the axle, on top? Do you have a Panhard link or Watts link as well? Coilsprings or leafs?
The trick with multilink suspensions is to keep everything square and equally spaced, until you have to change it. Also maximise the dimensions if possible, but not by sacrificing squareness.
So for a starting point
in side view make sure that the length of the two longitudinal rods equals the length of the A arm, and that they are mounted as much below the axle centreline as the A arm is above, and that at design height everything is parallel tot he ground (ideally).
In plan view make it all symmetrical, and keep the arms square to the axle.
Now the fun starts.
Back in side view, that arrangement will keep the diff parallel to the gearbox output shaft (which is good), but if you have a lot of suspension movement the propshaft or the diff or the pinion nose may hit the floor, or the UJ may over-articulate. So often you shorten the upper arm to dip the pinion nose as the suspension rises, or move the body mounting point for the A arm down. You need to make a model or draw it out to make sure that you aren't plunging the prop shaft too much if you do this.
In plan view on our four link beam axle we angle the upper arms in a bit, but you've already got that in spades, so I'd leave the lower arms parallel.
You'll need to post some more details and dimensions if you want to go further than that. Incidentally from the drawings I've found most non racers angle the upper and lower arms towards each other in side view.
oh one other thing - what is this suspension supposed to do? How much suspension travel does it have?
Cheers
Greg Locock
