Laydown shocks vs. 'shock tower' setup

[Origineelreclamebord]

Hi everyone,

I'm currently working on a project for a FWD buggy, and I don't know whether I want to go for laydown shocks or a regular shock tower setup. The thing is, I would love to make something narrow and streamlined, and laydown shocks would solve issues with space around the front for shocks (between gearbox and driveshafts/steering parts), but I am not very familiar with laydown suspension geometry or what I have to look out for when building a system like that.

I thought I'd put this up here, as the Pred has had both versions (at least, I saw some pictures of rear shock towers as an alternative to the rear laydown setup).

So my question is, are there big differences in handling between laydown and standing up shocks, and what do I have to look out for when constructing the geometry of a laydown suspension system? :confused:

[Cooper]

For laydown shocks it's VERY crucial to have the correct length of pushrods, shock shaft length, rocker angle in 'balance'. Very few people have this knowledge. So good luck!

[almunro]

This has been done before and looked good. Check out Team Kassanova K2.

http://www.rctech.net/forum/electric-off-road/419143-project-team-kassanova-k2v2-2wd-buggy.html

http://teamkassanova.webs.com/k22wdbuggy.htm

[Origineelreclamebord]

Thanks for the quick replies! :)

I could work out the right length of damper and pushrod in CAD software by tweaking a bit... But what do you mean by rocker angle in balance? I had a rocker arm system on a monster truck once that had bad geometry (because I tweaked with it but forgot about the influence on the geometry), and in the last part of compressing the suspension it felt like the suspension became easier to compress than in the middle:

http://www.tamiyaclub.com/getuserimage.asp?t=&id=img22450_08082011173412_4.jpg

This happened at a certain point. If you consider the distance between the pivoting point of the rocker arm and the shock as a line, when the mount of the rocker arm to which the shock was mounted past the point where the two 'lines' were perpendicular, the event occured - the suspension seemed to become degressive. Is this an example of what you mean by 'rocker angle (not) in balance'? :confused:

[Rebelrc]

In balance can mean one of two things on this type of setup
1 = push rod and shock are mounted both the same distance away from the pivot point of the rocker

2 = the mathematical equation that allows the pushrod and rocker to use all of the shock travel availible ... Leaving no unused area of the shock.
There are so many variables of this

So for example you could mount a shock that is 50% shorter and still do the same job by mounting it half way on the rocker between the pushrod side???
For example if the shock required for upright mounting was 30mm travel.
And its pushrod was mounted 20mm from the pivot on the rocker
Then you could mount a 30mm travel shock on that rocker with the same 20mm offset from the pivot.... Or you could mount a 15mm travel shock by mounting it on the rocker at 10mm from the pivot point
Hth

[Rebelrc]

Oils and springs would need to be doubled in weight/rate