Coilover/Single leaf/Pullbar rear end.

G'day guys, the modified class down here in Australia are bringing in a coil over/single leaf rear end set up that will allow a 22' biscuit pullbar only. Until now its just been a multi leaf springs with one shock per wheel, so this is quite a change. Can any of you blokes be kind enough to share a little knowledge or some photos to help me get my head around this change. Cheers.

Quote:

---

Originally Posted by stewballs

G'day guys, the modified class down here in Australia are bringing in a coil over/single leaf rear end set up that will allow a 22' biscuit pullbar only. Until now its just been a multi leaf springs with one shock per wheel, so this is quite a change. Can any of you blokes be kind enough to share a little knowledge or some photos to help me get my head around this change. Cheers.

---

I'll try to keep this short:

Multi leaf: The leaf springs hold the rear end in place as well as act as springs for the car and control axle wrap all in one system/part

The Mono leaf/coilover/pull-bar separates several of these item to multiple parts.

1. The primary objective of the mono leaf is just to hold the axle in place front to back (like a link suspension) and side to side (like a panhard bar would). So now the leafs primary job is to control the steer the axle see's by how the leaf is mounted and to keep the rear end in place side to side. Since the leaf is pretty flimsy it can't completely hold the weight of the car, thus uses coil overs to handle the biggest part of that and a pull bar to mostly control the axle wrap and control and direct that part of it.

A: It's now easier to change rates on LR or RR by changing the spring in the coilover over changing the whole leaf spring to another rate.

B: You can now mount the leaf in different angles front to back to alter steer

C: You can now install a pull bar to alter how and where it lifts on chassis and where it loads the rear end. Before with the multi leaf, it was acting as a ladder bar to a degree controlling the axle wrap.

D: If your rules allow a half leaf, you may want to go that route so you can install a pan hard bar and have some control/adjustment over the rear roll center and allow easier adjustments to rear side to side measurements. The half leaf, basically uses the front half of a leaf spring as a bar like a 2 link suspension but requires the front busing of the leaf to have a mono ball type bearing instead of a bushing to allow it to move left to right without binding like the bushing would.

Quote:

---

Originally Posted by billetbirdcage

I'll try to keep this short:

Multi leaf: The leaf springs hold the rear end in place as well as act as springs for the car and control axle wrap all in one system/part

The Mono leaf/coilover/pull-bar separates several of these item to multiple parts.

1. The primary objective of the mono leaf is just to hold the axle in place front to back (like a link suspension) and side to side (like a panhard bar would). So now the leafs primary job is to control the steer the axle see's by how the leaf is mounted and to keep the rear end in place side to side. Since the leaf is pretty flimsy it can't completely hold the weight of the car, thus uses coil overs to handle the biggest part of that and a pull bar to mostly control the axle wrap and control and direct that part of it.

A: It's now easier to change rates on LR or RR by changing the spring in the coilover over changing the whole leaf spring to another rate.

B: You can now mount the leaf in different angles front to back to alter steer

C: You can now install a pull bar to alter how and where it lifts on chassis and where it loads the rear end. Before with the multi leaf, it was acting as a ladder bar to a degree controlling the axle wrap.

D: If your rules allow a half leaf, you may want to go that route so you can install a pan hard bar and have some control/adjustment over the rear roll center and allow easier adjustments to rear side to side measurements. The half leaf, basically uses the front half of a leaf spring as a bar like a 2 link suspension but requires the front busing of the leaf to have a mono ball type bearing instead of a bushing to allow it to move left to right without binding like the bushing would.

---

Thanks for the generous response billetbirdcage. It was great reading your run down about the way this system works.