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  #1  
Old 04-02-2016, 09:26 PM
De Ranged's Avatar
De Ranged De Ranged is offline
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1/4 elliptical suspension Q?

I'm working on the design for my toy... an old series 3 landrover sort of a general club/winch challenge toy

I 4 linked the rear to try out something odd I found playing with a version of triaged calculator... found that by running alot longer lower link to the point its mounted to the back of the axle I got AS doing the reverse of accepted suspension results, as my suspension extends my AS drops... my theory is this will make a shorter WB more stable on steep climbs
The first weekend out proved worthwhile enough I need to try it with more HP
So I've cut the truck at the fire wall and I'm dropping in our version of a buick 3.8 due to my choice of chassis style a 1/4 leaf spring suspension is going to be easier to fit

Now to my question after trolling through lots of vintage threads on this style, I've kept finding reference to this style being dangerous on the front end and from some respected builders this is why I'd like some confirmation on my views

Here are some of the points put forward and my views

Excessive brake dive
This I see is a fault of the links, not enough Anti-dive (AS but on the front) or they have excessive travel and the spring rate is soft allowing more than normal up travel

Unloading
I'm guessing this one was from a truck with hinged packs lol something I don't believe is safe, I spose it could be argued that with a clamped multi leaf pack could unload as the main leaf drops but I don't see this being any different to a tender spring unloading on a coilover

Vage/Unpredictable steering
I don't know how the springs could cause this, I see this being caster angle, toe in/out, links and roll axis angle, the link triangulation or the style of link joints or very possibly the silly hinged packs unloading

The rest of the posts were classic pirate style lol little to no tech and lots of very direct opinion

To me the link geometry is more important the spring is just that a spring the leaf spring just has a different mounting position in my case under the floor with my top links and works out better for me (also they are cheaper I have stacks of them lol and given this is all about proving the daft idea in the back I like cheap)

Am I right.... have I missed anything?
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  #2  
Old 04-03-2016, 12:44 PM
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entropy entropy is offline
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I'm a little foggy this morning.
Will this be a 4 link and the spring is just a spring?
~or~
Will this be a 4 link and the spring will be a link?

Need more kaffie

E
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Old 04-03-2016, 03:09 PM
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De Ranged De Ranged is offline
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I've never considered that....
If the leaves are used as links in a 4 link they would allow movement of the axle... I could see caster change due to rotation both from the rubber mount in the eye and the leaves change in link length due to flex
You wouldn't need so much triangulation on the links either
If setup right could be made to rotate the pinion due to the change in link length as the spring curls/straightens

Hmmm interesting idea, it would take alot of planing to setup to make these issues work positively but could make for a resemble weight saving

No I wasn't planing anything like that... a standard 4 link with the leaf spring separate acting as just a spring
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Old 04-03-2016, 05:13 PM
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Quote:
Originally Posted by De Ranged View Post
SNIP< a standard 4 link with the leaf spring separate acting as just a spring
I do not see the issue a spring is a spring at least that is what I think today. As long as you allow for the various movement of the leaf spring such as attaching the spring to the link via a SRE and shackle to the spring eye....

E
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Old 04-04-2016, 04:48 AM
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De Ranged De Ranged is offline
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Thats what I thought till I found a threads where some respected names stated on the front its dangerous
I'm not going to name any of them lol we all make mistakes, its just I respect them enough I had to ask

And as one of those I respect E you backing my thoughts I'm happy to proceed

oh and here's a couple of shots of the rear links what started it all




Ignore the amount of flex thats there because I happened to have a set of 14" procomps (cheap long travel shocks) I didn't see any point in putting fruity bits on a dog lol $400 landy so an entire Achilles heel of a drive train and an old weak diesel motor with no hp... bloody good laugh tho
The rear end performed well enough I had other guys with comp style trucks parking up to watch my rear end in action lol in a non dodgy way
So all this is turning the dog into a bit of a tart so I have some hp and a solid drive train so I can abuse it and really test it

Thank you
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