Suspension 3d Model?

[PapaJim13]

Hi, I am an engineering student trying to design custom sway bars for my 2013 fiesta. I mostly just want to see what it will do. Does anyone have 3d models or drawings for any/all suspension components?

 

[WannabeST]

I dont have any 3D modeling, but out of curiosity what are you looking to do

 

[PapaJim13]

While racing, speed is key, but the track inevitably curves from left to right causing a need to brake, turn, and accelerate. All these inputs cause weight transfer across the vehicle’s 4 tires leading to unequal tire loading from right to left as well as forward and back. An increase or decrease in a tire’s normal force on the ground will affect the amount of “grip” (lateral and fore/aft force the tire can withstand before slipping over the pavement) available. In turning situations it is important that no tire looses traction, it could lead to loss of traction in more tires, potentially leading to a loss of control and a crash. To take turns as fast as physically possible, a more equal grip on the road surface is needed. Front and rear sway bars exist already to counteract roll (lateral weight transfer) but there are no forward to rear sway bars to prevent fore/aft weight transfer caused by braking and acceleration.

IE: I want to power through turns and keep front wheel traction, another added benefit is it will prevent lift off oversteer.

 

[WannabeST]

So if I am understanding correctly, you want a swaybar that connects from front to rear in order to prevent things like nose dive under braking?
Isn't the yaw going front and back mostly the job of the shocks and springs

 

[PapaJim13]

It absolutely is, but I've never heard of a system like this and and wanted to make it just to see what would happen. I feel like there would be another level of control as there is a physical linkage between the front and the rear. No shock/spring is able to relate the vertical position of the front wheel to the rear wheel and vice versa. Do you think this would have any beneficial effect?

 

[WannabeST]

It absolutely is, but I've never heard of a system like this and and wanted to make it just to see what would happen. I feel like there would be another level of control as there is a physical linkage between the front and the rear. No shock/spring is able to relate the vertical position of the front wheel to the rear wheel and vice versa. Do you think this would have any beneficial effect?

The idea sounds good but does not sound practical if I am being honest. As someone who competes. I want my car to be simple with no added complexity.
I understand the benefit of wanted to control the front to rear yaw motions.
However this kind of idea would come at the cost of:
1 - space, I think the packaging of this would be hard to accomplish
2 - more linkages = more parts to fail, inspect, and maintain
3 - weight, even a lightweight material would add up given the length needed

This comes from an idiot who just drives, competes a little and does not have any college degree. So take it with that grain of salt.

If I was to make a suggestion for Fiesta ST suspension engineering, I think time would be better spent on ideas like:
1 - Billet front up rights, could allow for more caster, tie rod location, potentially 4x100 and 5x114.3 hubs
2 - spherical tie rods - this would be simple and low engineering needed
3 - custom rear twist beam - I know the twist beam could be lighter but the rigidity will affect lateral load.
In a perfect world, I think a custom twist beam with maybe some easy to sway bars would be awesome
This would require the most research and engineering. But I think it would be the coolest, I imagine a small handful of drivers in here would love less unsprung weight with easy to swap rotation.
(Again I'm just a dummy that spends money on an SE lol)

 

[PapaJim13]

I agree space, complexity, and weight will be challenges to overcome but I figured it would be cool for a proof of concept.
I am currently in the works of planning an AWD swap using (don't hate me) an LS engine, 4L80 trans, BW4472 transfer case, and maybe a C4 corvette complete IRS setup. I feel like the planned ~4x power to the front and rear wheels will cause weight shift like never before and it would be cool to see what the added linkages might do before I design my entire car.

I'll have to graduate before I have the funds to support such a project but a Fiesta RS will be in the works.

 

[SteveS]

It was done by Alec Issigonis via hydraulics. On the Austin 1100, called hydrolastic suspension. Except they used it for the opposite effect--to soften things, which resulted in more pitch and dive.

 

[PapaJim13]

Looking more into that, the Citroen 2CV has a similar idea behind their design. I would want to keep the traditional shock/spring setup under all 4 corners with front, rear, and side sway bars.

 

[sonicmn]

It was done by Alec Issigonis via hydraulics. On the Austin 1100, called hydrolastic suspension. Except they used it for the opposite effect--to soften things, which resulted in more pitch and dive.

I think the mid-2000's Toyota 4Runners had something similar. I remember learning about it from a friend after one of the fittings failed in like 2015 in the salt in MN. Looking it up, I think it was called XREAS. Kinda of a neat idea for a big floppy truck!

 

[Dpro]

why just why? 😂You’re making things complicated for the sake of being complicated.

 

[PapaJim13]

Cus I want to know what it would do. I enjoy designing and making stuff, it seems like a cool idea to me. It seems like could be added benefit from a system like that. Additionally a rear favored awd transfer case is going to squat my car a lot more under wot than currently. Might as well try it before I gut my car.

 

[Austin_Lee]

Not to bring a dead chat back but look into anti effects.
https://suspensionsecrets.co.uk/anti-squat-dive-and-lift-geometry/
When the wheel doesn't move directly inline with the caster angle under compression, it can create a rotational force that counters dive/squat.

 

[PapaJim13]

This is amazing. I'll be saving this for later when I decide on the angle to put my rear suspension at.
Very informative thank you.