Thread: Coil over shocks

Originally Posted by Grimace

With the rear aframe suspension the shock location is better to be forward of the differential.

You utilise the travel of the shock better as the axles drops it moves forward

that makes sense, didnt think of that.

So why is it that on the front the shock is inside the spring then? is that just to keep it out of the way of steering etc

Originally Posted by Ace

that makes sense, didnt think of that.

So why is it that on the front the shock is inside the spring then? is that just to keep it out of the way of steering etc

Yes. (plus the bodywork is a bit of a problem for an outside mount like on the back, but mainly steering etc I think)

John

have been told that to have coil overs fitted onto a live axle 4wd (such as a land rover) it needs to be engineered because the mounts need to be welded to the chassis hence most mods to a chassis needs to be engineered from what i see coil overs have an advantage because if you get one that is rated at 14" of travel once it reaches that length thats it but with a normal coil shock setup if the shock is not matched to the spring or vice versa there is travel issues but then again there is alot of mods that can be done to normal suspension that can get extreme amounts of flex out of (dislocation cones is a start)
also coil overs are quite expensive i got a rough price the other day and i was told around the $800 EACH mark and im asuming if you were to go for something such as fox shox they might be even more expensive

triangulated 4 link with coil overs would be a good idea i rekon

In some ways it's just easier to go opposed as the holes are already drilled in the chassis for the mounts, at least on the RHS chassis rail on late model Defenders and RRC's, but as Grimace suggested you get better utilisation of the shock stroke in droop with a forward mounted damper in the rear.

Originally Posted by Ace

that makes sense, didnt think of that.

So why is it that on the front the shock is inside the spring then? is that just to keep it out of the way of steering etc

Originally Posted by JDNSW

Yes. (plus the bodywork is a bit of a problem for an outside mount like on the back, but mainly steering etc I think)

John

Ideally you want the damper at near 90* to the axle and as far outboard as possible for maximum control. (all things being equal)

Without muddying the waters too much, as you lean a damper/shock absorber in relation to axle travel you reduce the effective shaft/piston movement.

A damper works by converting kinetic energy to heat (and then dissipating it) so if you can maximise the stroke of the piston in relation to axle movement you reduce the internal forces need to control the axle and chassis.
As you incline a damper you correspondingly need to increase the valving to control a given spring rate and chassis mass as you are effectively reducing it's working travel.
The only time this works against you is in mega travel off road racers where you reduce the motion ratio that the damper sees as
a) you can't physically get a damper long enough
b) shaft speeds become excessively high, generating excessive friction and heat.

Dampers are inclined mainly due to packaging constraints, eg. you just can't jam a long enough stroke damper in above the axle, so you use a shorter stroke damper and incline it for a given axle travel.

Obviously, as travel increases and the axle subscribes an arc, both side to side and forward and aft, the relationship between piston shaft and axle travel varies too and so you can arrive at a rising and falling rate of shaft to axle movement, depending on where you are in the stroke.

Originally Posted by c.h.i.e.f

have been told that to have coil overs fitted onto a live axle 4wd (such as a land rover) it needs to be engineered because the mounts need to be welded to the chassis hence most mods to a chassis needs to be engineered from what i see coil overs have an advantage because if you get one that is rated at 14" of travel once it reaches that length thats it but with a normal coil shock setup if the shock is not matched to the spring or vice versa there is travel issues but then again there is alot of mods that can be done to normal suspension that can get extreme amounts of flex out of (dislocation cones is a start)
also coil overs are quite expensive i got a rough price the other day and i was told around the $800 EACH mark and im asuming if you were to go for something such as fox shox they might be even more expensive

triangulated 4 link with coil overs would be a good idea i rekon

you might want to look abit harder i paid $240usd per swayaway 2.0'' emulsion shock, $70usd for the slider kit and $55usd per eibach coil.
fox and king are more expensive but still not $800 ea imported atmo.

cheers phil

Originally Posted by c.h.i.e.f

have been told that to have coil overs fitted onto a live axle 4wd (such as a land rover) it needs to be engineered because the mounts need to be welded to the chassis hence most mods to a chassis needs to be engineered

Actually the top perch is below the upper mount so it's fine.