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New nutso idea...(suspension)

Posted: Tue Nov 27, 2007 9:45 pm
by 90Mav
well my N/A NOS td42 idea is crawling to a halt since i cant figure out the fueling :cry:

So now i have a new crazy idea... :lol:

Was thinking of rear suspension setups, as im going to ditch the H260 for a 233, and will need to do something for suspension. (welding leaf mounts on seems too easy :roll: )

Was thinking about a reverse a frame sort of thing with a watts link..

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Hope this drawing makes some sense to you all.

this idea has been in the back of my mind for some time, so i would really appreciate some feedback
( i also have some more ideas on springing it, was thinking of a central airbag, with tortion bar anti roll..)

so anyway what do you think? (flame suit on)

Posted: Tue Nov 27, 2007 10:39 pm
by GRIMACE
easier to just do a standard aframe or double triangulated rear.

Posted: Tue Nov 27, 2007 10:49 pm
by ozy1
ive thought about the watts link prevoiusly, but then i had a though, what happens when the rear end jumps, diff drops and the entre pivot on the wats link rotates and ends upparalell to the ground, on landing there is a sudden thump with all force pushing into your chassis rails

i wasnt a fan of this idea so i left it alone,

but give it a try if you want and see what happens

Posted: Wed Nov 28, 2007 6:30 am
by professor
This is very similar to the unimog torque tube design but the unimog has just a panard and the tail shaft runs up the torque tube.

great thinking! no reason why it wont work. just keep the front mount close to the tail shaft and make the wats link adjustable.

Chad

Posted: Wed Nov 28, 2007 7:06 am
by lay80n
Search on pirate for one link style suspesnion. There is a fair bit of tech on there. You will find you will get huge Anit Squat numbers from your drawing above, as the IC will be pretty high above the 100% Anti Squat link (just a guess from your drawing and the likley layout of a rig). It will also increase in Anti squat as the rear droops out.

Link from pirate for you to read - http://www.pirate4x4.com/forum/showthread.php?t=235977

Layto....

Posted: Wed Nov 28, 2007 7:17 pm
by Gwagensteve
One links can work (Unimog) but because of the use of the torque tube and portal diffs the driveline torque puts NO influence into the suspension. I planned a one link front end for my suzuki for ages as it will suck the front down under power.

I own a car with massive anitsquat - the G wagen - and it can get very odd under big compound angles under power.

Watch the roll centre too - it looks very high and I'm not sure that the watts link and the a frame trying to rotate around a different point might cause some binding effects, especially under power under large articulation.

The one link will have to deal with very large loads and will be prone to failure. Have a look at evolution's 3" joints - they look strong enough, and were what I was planning to use.

Just some Ideas. It's not an out of this world idea - it should work fine if well designed and constructed.

I'd try an get the link as horizontal as possible at ride height.

Steve.

Posted: Thu Nov 29, 2007 10:38 am
by 90Mav
Thanks for the replies. I'll do some measurements and draw it up properly on the weekend

Posted: Fri Nov 30, 2007 4:39 pm
by 90Mav
Ok i did a half assed scale drawing of the rear end, and if i take the COG as being 500mm??? above the sills, then i can still have some AS if i mount the one link below the tailshaft.. (bottom blue line)

no idea how to calculate it as a percentage though (it is 70mm(purple line) above the 100%AS line if anyone knows how to do this) could be more if i shortened the link, but i want to avoud this if possible.

if i had it above the TS then it would be more like 330mm above the 100%AS line (green line) this seems unworkable?

basically the link would be where the crosmember is below the uni, that the body safety links are on (would replace the crosmember) GQ patrol


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Read the thread on pirate. some good ideas, i think ill use a tow ball for my hitch... NOT
Gwagensteve wrote:Watch the roll centre too - it looks very high and I'm not sure that the watts link and the a frame trying to rotate around a different point might cause some binding effects, especially under power under large articulation.
Wouldn't the roll center be at the center of the watts link? i see what you mean about binding though, but if i had the link under the TS then it shouldnt be a problem.

Posted: Fri Nov 30, 2007 5:09 pm
by 90Mav
This joint looks like the go but would it allow enough articulation? only has 28deg of deflection, which i spose is a bit, but may be not enough?

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Posted: Fri Nov 30, 2007 5:38 pm
by 90Mav
ran a few numbers in the 4 link calculator (have no idea what im doing) and setteled on 128% AS for under the tailshaft 205% :shock: over the tailshaft

128% seems like a nice number yes?

Posted: Fri Nov 30, 2007 6:56 pm
by 90Mav
also found this looks the goods but uses a tow ball, and i'd be a bit iffy having my whole rear end hanging on one nut....
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Posted: Fri Nov 30, 2007 7:36 pm
by 90Mav
Wait... i have it..

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36deg with 1" bolt :twisted: