New suspension system, design for your car?
Discussion
Hi, Im a student of motorsport engineering. For an assignment I had the brief of designing a suspension linkage system to allow wheel rate adjustment and change in wheel rate adjustment. Now this sounds complicated, it kind of is, but ive successfully made a prototype for a formula student car.
It works by changing the relative pivot positions within the linkage. It offers different suspension stiffnesses and different rates of progression that have a wide and effective range.
This would be used instead of having a range of coil springs. The designed prototype has 12 usable settings, it could save a lot of money, you would only need one set of coils.
It has been designed for sprinds mounted inboard, however the concept could be applied to macferson struts, depending on packaging.
Im interested to here about anyone views on this product.
What do you think? would you use this system on your car?
Cheers, Andy
It works by changing the relative pivot positions within the linkage. It offers different suspension stiffnesses and different rates of progression that have a wide and effective range.
This would be used instead of having a range of coil springs. The designed prototype has 12 usable settings, it could save a lot of money, you would only need one set of coils.
It has been designed for sprinds mounted inboard, however the concept could be applied to macferson struts, depending on packaging.
Im interested to here about anyone views on this product.
What do you think? would you use this system on your car?
Cheers, Andy
What's the advantage? Changing springs or damper settings is pretty straightforward - is tweaking your setup easy too? Can you guarantee similar behavior during cornering for different stiffness settings - i.e. similar wheel paths / camber changes?
Edited by Cathar on Sunday 18th June 10:27
It isn't clear why you would want to do this other than as a design exercise. There's really no reason to make a production car suspension adjustable - it's more weight/complexity/cost and enables the customers to mess up your carefully chosen suspension settings.
The people most likely to want this sort of adjustability are low volume/one-off track cars and racers. The cost of springs are trivial compared to the weight/complexity of extra linkages. But being able to adjust the spring rate within seconds rather than minutes might be worth while. Since you're using linkages and joints you should be considering an inboard system, make it modal while you're at it.
The people most likely to want this sort of adjustability are low volume/one-off track cars and racers. The cost of springs are trivial compared to the weight/complexity of extra linkages. But being able to adjust the spring rate within seconds rather than minutes might be worth while. Since you're using linkages and joints you should be considering an inboard system, make it modal while you're at it.
Cathar said:
What's the advantage? Changing springs or damper settings is pretty straightforward - is tweaking your setup easy too? Can you guarantee similar behavior during cornering for different stiffness settings - i.e. similar wheel paths / camber changes?
Edited by Cathar on Sunday 18th June 10:27
The advantages are providing the user with a wide range of spring stiffnesses and charachteristics quickly and relatively cheaply. The adjustment is simply done by using an eccentric cam. A locking bolt is unscrewed and the cam moved to the required position.
the system is designed to give a range of adjustment suitable to the car it is designed for. I have made a prototype for our 2005 formula student car and tests have proved successful.
Edited by andylewis1986 on Sunday 9th July 21:35
GreenV8S said:
It isn't clear why you would want to do this other than as a design exercise. There's really no reason to make a production car suspension adjustable - it's more weight/complexity/cost and enables the customers to mess up your carefully chosen suspension settings.
The people most likely to want this sort of adjustability are low volume/one-off track cars and racers. The cost of springs are trivial compared to the weight/complexity of extra linkages. But being able to adjust the spring rate within seconds rather than minutes might be worth while. Since you're using linkages and joints you should be considering an inboard system, make it modal while you're at it.
The people most likely to want this sort of adjustability are low volume/one-off track cars and racers. The cost of springs are trivial compared to the weight/complexity of extra linkages. But being able to adjust the spring rate within seconds rather than minutes might be worth while. Since you're using linkages and joints you should be considering an inboard system, make it modal while you're at it.
The system isnt really aimed towards road car users who dont know what there doing. It is more aimed towards racers, it provides adjustability with little extra wieght. The prototype made was only marginally heavier than the linkage compontent it replaced.
Edited by andylewis1986 on Sunday 9th July 21:39
Are you just altering the installation ratio to get a different wheel rate with the same spring?
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
Mr Whippy said:
Are you just altering the installation ratio to get a different wheel rate with the same spring?
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
It changes installation ratios and the rate of change of installation ratios. The current system works on a double wishbone set up with inboard dampers/coils. the concept could be applied to a Mcp strut, it would adjust the pick up points of the pivots.
andylewis1986 said:
Mr Whippy said:
Are you just altering the installation ratio to get a different wheel rate with the same spring?
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
It changes installation ratios and the rate of change of installation ratios. The current system works on a double wishbone set up with inboard dampers/coils. the concept could be applied to a Mcp strut, it would adjust the pick up points of the pivots.
Ah sounds pretty cool. So eccentric movement giving rate of change of IR
So I guess with that you can basically get variable rate springing... Does the damper also pickup on the same points as the spring so it is effected the same way by the IR?
I guess if it's compact and light it'd be great for track day cars, you could adjust more things a bit more quickly and easily.
But can't coilover/adjustable's inboard do that just as well? Kinda like the Koeningsegg CC8S inboard jobbies?
Dave
Mr Whippy said:
andylewis1986 said:
Mr Whippy said:
Are you just altering the installation ratio to get a different wheel rate with the same spring?
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
Sounds simple enough if you've done it without adding lots of extra weight or it interfering with other components... if so how does it work on a McP strut? Is it a Pseudo McP with top and bottom wishbones (johnny wishbone basically, like on new C6 Vette iirc)
Dave
It changes installation ratios and the rate of change of installation ratios. The current system works on a double wishbone set up with inboard dampers/coils. the concept could be applied to a Mcp strut, it would adjust the pick up points of the pivots.
Ah sounds pretty cool. So eccentric movement giving rate of change of IR
So I guess with that you can basically get variable rate springing... Does the damper also pickup on the same points as the spring so it is effected the same way by the IR?
I guess if it's compact and light it'd be great for track day cars, you could adjust more things a bit more quickly and easily.
But can't coilover/adjustable's inboard do that just as well? Kinda like the Koeningsegg CC8S inboard jobbies?
Dave
yea it actually can give adjustable and progressive damping if wanted. I have pics of a prototype on a FS car. How do you paste photos on here?
Its been aimed towards trackday cars and hill climbers to give a fast and easy way of making adjustments.
Cant say ive see the cc8s suspension system, but most i have seen are much less adjustable. The prototype has 12 settings.
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