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Stanguellini FJ Wire Suspension


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#1 rbm

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Posted 20 October 2019 - 16:27

On the early Stanguellini Formula Juniors, the rear live axle is transversely located using a pair of wires, NS chassis tube to OS axle end and vice versa.

 

does anyone have any pictures of how was set up, I assume it must have been adjustable? and how did it cope with the change in triangulation (wire length needed) on bump, droop and roll?



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#2 MalcolmC

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Posted 20 October 2019 - 20:29

In the book 'Stanguellini - Big Little Racing Cars' by Luigi Orsini & Franco Zagari there's a drawing on page 319 showing the arrangement as applied to the 750 Sport Internazionale (not an FJ).

 

The cables are to the rear of the axle and attach to the axle at the coil-over damper mounts (also located behind the axle tubes).

 

The lower chassis rails pass under the axle. Brackets on the rails (also to the rear of the axle) stand up to about the height of the axle. The cables attach to these brackets and the offset from the chassis rail is possibly sufficient to create a torque tube effect.

 

With the cables at the same height as the axle when at rest, any movement of the axle up or down would increase the tension in the cables and try to pull the tops of the brackets inboard.

 

The caption for the drawing says the cables were adjustable.


Edited by MalcolmC, 20 October 2019 - 20:35.


#3 Ray Bell

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Posted 21 October 2019 - 05:12

It sounds like it relied on wires stretching and tubes bending and twisting...

Not a totally positive method of lateral location, but simple, cheap and acceptable.

It would also have increased the effective spring rate on bump, reduced it on rebound.

All of which reminds me that I once read somewhere that the 30/98s had more flex in the chassis than in the springs...

#4 Garsted

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Posted 21 October 2019 - 13:25

It sounds to me as if each cable functions like a Panhard rod, but as cables can only be loaded in tension two are required working in opposite directions.
Steve

#5 rbm

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Posted 21 October 2019 - 16:53

so the wires run from the the two brackets with the holes in the picture (one by the OS damper and the single up stand on the NS) 

to a special nut on the lower damper mount (unfortunately the only one I have has been butchered).

48936349133_e532b31a5f.jpgIMG_2346 ,

 

48936354503_d80cc0294c.jpgIMG_2345


Edited by rbm, 21 October 2019 - 16:58.


#6 MalcolmC

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Posted 21 October 2019 - 20:43

Yes, those are the same mounting points shown in the drawing. The lower chassis tube cross-member isn't on the drawing though.

Also it looks like the OS mount is welded to the chassis upright so my torque tube theory doesn't stack up. Perhaps there're would be sufficient elongation with a woven wire/cable as the strands contract under tension?


Edited by MalcolmC, 21 October 2019 - 20:49.


#7 Lee Nicolle

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Posted 22 October 2019 - 09:17

so the wires run from the the two brackets with the holes in the picture (one by the OS damper and the single up stand on the NS) 

to a special nut on the lower damper mount (unfortunately the only one I have has been butchered).

48936349133_e532b31a5f.jpgIMG_2346 ,

 

48936354503_d80cc0294c.jpgIMG_2345

Do you think that shock bottoms out?



#8 Ray Bell

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Posted 22 October 2019 - 12:23

Probably when the rear brakes are applied...

#9 rbm

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Posted 22 October 2019 - 18:48

well as it has no rear springs and spent over eleven thousand miles in a container.....