Formula BMW Suspension

[RacingManiac]

Actually, it looks as if there is no suspension for roll movement.

Very stiff, and undamped.....

[Powerslide]

You mean the tree the coil spring is mounted on can actually twist? It looks solid and un-adjustable. Just looks though.

[MrT]

It's quite simple -

In bump, both rockers rotate in the same direction, so the T-bat ant roll bar pivots back and forth and actuates the spring and damper.

In roll, the rockers rotate in opposite directions, so the t-bar anti roll bar does not pivot at the bottom, but instead twists. This twist is what resists the roll, with a stiffness and damping charecteristic of the roll bar itself.

Of course you can get bump and roll together, this gives a combination of the two above and can also be ruddy dufficult to calculate the combined stiffness and damping.

[RacingManiac]

You mean the tree the coil spring is mounted on can actually twist? It looks solid and un-adjustable. Just looks though.

It can be adjusted via spacer that shims the distance from the ARB link to the center of the "tree" of T-bar....

[Gmuze]

Hi, there i'm new here and am currently looking into monoshocks for fsae.

Looking at the connection of the spring damper to the ARB. To the left of it has some kind of damper (both pictures), could any one tell me what these are for?

I know it's an old topic, but i do have some comment on a previous post by MrT. He states during bump both rockers move the same way. This is movement is actually called parallel bump and happens during (straight line) braking and acceleration, also known as dive and squat.
Bump happens due to irregularities of the surface and acts on one of the wheels more than the other. This kind of configuration of the monoshock has bad properties if it comes to handeling these irragulatities and that's why they are only useful on clean/flat tracks.

[zac510]

Looking at the connection of the spring damper to the ARB. To the left of it has some kind of damper (both pictures), could any one tell me what these are for?

I'm not sure which part you are talking about. Is it the damper reservoir?

[Gmuze]

On this picture you can see a 'thin damper' connected, just left of the 'main springdamper', to the T-bar. The other side is connected to the damper resevoir. The 'thin damper' crosses the 'main springdamper'.
On the first picture you can see the same thing, except that the 'thin damper' is not connected to the damper resevoir but simply to the chassis through a bracket.

ps. I may be new, but i'm pretty sure I know what a damper resevoir is

[zac510]

hehe no worries
That looks to me like an electronic sensor for measuring the movement of the spring.
It looks like ordinarily it would connect to the little stud that is situated on the chassis to the left of the spring, but for some reason the mechanic has disconnected it.

[RacingManiac]

On this picture you can see a 'thin damper' connected, just left of the 'main springdamper', to the T-bar. The other side is connected to the damper resevoir. The 'thin damper' crosses the 'main springdamper'.
On the first picture you can see the same thing, except that the 'thin damper' is not connected to the damper resevoir but simply to the chassis through a bracket.

ps. I may be new, but i'm pretty sure I know what a damper resevoir is

Thats a Linear Potentiometer, used to measure shock movement....

[Scuderia_Russ]

Yeah, it's for data acquisition. I was up there at the weekend too with Coles Racing. More info about that in the Woo-Hoo thread in off topic tommorrow at some point.

[Lafora]

i think if one were to do a mono for fsae, u'd better reference the 2 litre renault designs and not the mygale bmw designs.

not the best mono out there, that's for sure.