Hello all...
Which layout is stiffer in your opinion - 1 ton car, RWD, i can do both but need to choose one.

Depends more on your chassis than anything else, (1) Is more or less what was used on the Lotus Elan, (2) is late 1960s F1 best practice.

Originally i have OE wishbone inboard points and it will suit variant 1, optionally for variant 2 i can use additional arm. I can do both with no worries, just need to be safe.

Option 1 for me, weld it solidly with some gussets and mount the hub carrier on rose joints so you can easily adjust toe. Do not run the bars parallel but spread across the chassis to spread the load.

Top wishbone as a simple triangle adds strength and sets camber, just make sure there is room for the shock if locating on the lower bone.

Here's mine, you cannot see the other straight tube but it's still there

Description

[Edited on 12/3/14 by mark chandler]

Thanks for your advice, i wont have upper wishbone on this, just lower and shock macpherson strut on upright....
Actually option 1 will be faster and easier to make.
Any advice on seamless tube size - guess 34mm OD with 3mm wall will be fine?

[Edited on 12/3/14 by FERRARIST]

option one puts the diagonal in compression in a forward motion. option two puts the diagonal in tension in a forward motion. option 2 could theoretically be made lighter.

you could go for the ultimate and use both diagonals.

Two diagonals has potential problems to cause problems.

Option (2) is very easy do do using separate links, doing it this way allows for easy adjustment of rear castor, strange as it may seem there is such a thing.

Option (1) can either be as wishbone + single link or as complete suspension arm but former is a better option.

This might be of interest --- http://www.spydercars.co.uk/lotus-elan-2-wishbones/

Maybe it's worth to mention that:
- Car is RWD
- 1050kg
- Setup in question is for rear axle
- 580 kg weight on rear
- 250bhp......
- 250/64/18 - 270/65/16 full slicks used all time.....

[Edited on 12/3/14 by FERRARIST]

quote:

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Originally posted by FERRARIST
Thanks for your advice, i wont have upper wishbone on this, just lower and shock macpherson strut on upright....
Actually option 1 will be faster and easier to make.
Any advice on seamless tube size - guess 34mm OD with 3mm wall will be fine?

[Edited on 12/3/14 by FERRARIST]

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Well neither of above layouts used, i choose another option. purely because there is no need to modify rear subframe or original mounting points.
Trailing arm, and 2 transverse arms, rear arm used for toe, front and rear for camber......trailing arm length can vary and i can adjust inboard height of the arms in order to experiment with different roll center. 18mm rose joints all around.....
I wish both arms to be 5-6cm longer than that, but camber did not changes more than 0.2 degrees top to bottom wheel travel.
Any suggestions or cons that you can advice?





[Edited on 21/5/14 by FERRARIST]

you should have a longer bolt there, so it protrudes through the nylon of the nut.
single shear on the trailing arm not ideal, but given the size and very little moment on it, no problem.

Also have you checked clearance of the sphhericals through the suspension range?
Again, the front one looks pretty close to the chassis already, much droop and it looks like it'd bind on the body

quote:

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Originally posted by 43655
you should have a longer bolt there, so it protrudes through the nylon of the nut.

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quote:

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Originally posted by 43655Also have you checked clearance of the sphhericals through the suspension range?
Again, the front one looks pretty close to the chassis already, much droop and it looks like it'd bind on the body

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