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Here a rendering of the alu transaxle we are planning to built for my 3.2 75 tracktool.
Aim was fully adjustable rearsuspension, and reducing unsprung weight as much as possible.
Result sofar is 10 kgs off.
It is almost ready for production now, but before starting I would like to hear your opinion on this project.
Does it make sense?
It is not a commercial project, we own a metal working shop, and the drawings have been made by one of our trainees, so it hasnt cost much sofar.

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I say it kicks assss!

Nice rendering pictures.

But I have serious doubts about this one.
Don't get me wrong here, this is a gut feeling thing. I'm just judging rendered pictures.

Do you home work absolutely to the full extend, look seriously into load cases, stresses etc.

The rationale behind my doubts:
- Aluminum when used in suspension parts, is forged aluminum.
- Welding on high stressed aluminum parts.
- When I look at the design: lightening/cuts are made in (to me) not the most obvious places.

Hi Maurizio, worried about what we are doing to your old car

The design is made in Solid Works, with all parts and the total assy stress-tested.
As you know I am not a technician, but i'll double check your doubts with my brother.
(We do have certified alu-welders working with us)

I'm with Maurizio on this one.
Just because you can weld alu doesn't mean you can properly design a stressed member in the suspension system..
Those shock absorber/coil over mounts look very strange and the cuts in the pieces that goes along the car looks totally crazy.

The thing about FEM is that unless you know EXACTLY how to apply the loads and constrain the parts you will get craaazy results. Also, it's an artform to interpret the results from a FEM analysis and it takes years if not decades to know what you're doing. Especially in an envirinment like the chassis of a car. We're talking life and limb here...

How will you attach the camber adjustment for instance?

Cazzo Super Veloce wrote:Hi Maurizio, worried about what we are doing to your old car

Oh no, you're going to properly use it, I can only appreciate that!
I'm more worried about you.

The design is made in Solid Works, with all parts and the total assy stress-tested.

Mats, wrote out what I was thinking.

Mats wrote:I'm with Maurizio on this one.
Just because you can weld alu doesn't mean you can properly design a stressed member in the suspension system..
Those shock absorber/coil over mounts look very strange and the cuts in the pieces that goes along the car looks totally crazy.

The thing about FEM is that unless you know EXACTLY how to apply the loads and constrain the parts you will get craaazy results. Also, it's an artform to interpret the results from a FEM analysis and it takes years if not decades to know what you're doing. Especially in an envirinment like the chassis of a car. We're talking life and limb here...

How will you attach the camber adjustment for instance?

Camber adjustment will be done IMSA-style, with a tie-rod.
Note that this is still only a model, and I don't like some of it's features (like the cuts you mention) either.
We will built in more than enough safety-marging. and if this means weight will go up too much, we'll stay with a steel triangel, combined with the camberadjustment you see in the rendering.

What if you went with kits to adapt current dedion to adjustable camber/toe. SO instead of replacing the whole dedion, just replace the end spindles. Just a suggestion. The focus would then be adjust ability instead of weight.

The stock dedion is pretty strong as is as as long as you don't hit a curb. I think for weight reduction, I will compromise elsewhere but not the suspension components. For example go for super light forged wheels from SSR or other known brand wheels. 17 x 9 ET 20 for 18 lbs is what I would consider light.

BTW, I like the fact that you allow for adjustable dedion pivot.

Sorry, don´t understand your last sentence?

The idea of an alu triangle came up after I disassembled the de Dion on my own.
Man, is this thing heavy...

I'm not gonna skip it yet, with clever construction methods I think it can be stronger than the steel
version.
And if not, like said we'll go for steel triangle with alu adujstable camber/toe parts.

I meant the watts linkage pivot mount to the dedion. It looks like you have several holes to mount it to.

OK, clear.
Copied it from a steel cambered Dedion we have as an axample.