Formula BMW Suspension

f1.redbaron · Post 29 Jun 2006, 20:58

Can somebody, please, explain to me, what is the point of that horizontal bar joining the two upper elements of the A-arm where they connect to the chassis (see arrow)? Thanks

EDIT: Reinforcement? But what would it reinforce?

Post 29 Jun 2006, 21:11

to help reduce a bending moment on the a arms and the mounting points

RacingManiac · Post 29 Jun 2006, 21:37

anti-intrusion bar....in the event of the crash so that the a-arm don't pierce into the tub from their mounting....and jab driver in the leg...

f1.redbaron · Post 29 Jun 2006, 21:51

flynfrog wrote:to help reduce a bending moment on the a arms and the mounting points

That is what I was thinking too, but then based on this picture below, you can see that the weakest point is the mounting point, and this "reinforcement" bar is just a few cm before it.

RacingManiac wrote:anti-intrusion bar....in the event of the crash so that the a-arm don't pierce into the tub from their mounting....and jab driver in the leg...

That makes sense...btw, did you get a chance to see them last weekend?

zac510 · Post 29 Jun 2006, 22:16

Does that have a torsion bar beneath the rocker arm?

RacingManiac · Post 29 Jun 2006, 22:33

No torsion bar, just monoshock...the roll is undamped....

The car that I am associated with finished 2nd in both race, I was there actually to take picture for the team....Matt Lee was the driver.

furnik28 · Post 29 Jun 2006, 23:05

irl and cart have them for anti intrusion. when they make the suspension arms first then drill the cross member so you can slide it on to the end of were the rose joints are then its welded in place.

i70q7m7ghw · Post 01 Jul 2006, 13:10

Do those arms have a pivot where they connect to the chassis, or are they just intended to flex?

zac510 · Post 03 Jul 2006, 11:27

RacingManiac wrote:No torsion bar, just monoshock...the roll is undamped....

How is the roll sprung then?

MrT · Post 04 Jul 2006, 20:06

The roll is sprung solely by the anti roll bar, which obviously has negligable inherant damping in itself. The Spring and damper unit only comes into action in 2 wheel bump/rebound........ horrible system really, although the aim was to seperate roll from bump, they are not truley seperated and roll stiffnesses can vary at different stages of the corner as the sping/damper unit comes in and out of effect.

luisandregg · Post 04 Jul 2006, 20:07

Isn't that central element (under the monoshock front mounting point) a torsion bar? It's linked to something looking like a damper, so it would absorb roll...

MrT · Post 05 Jul 2006, 09:03

No, only damper in the whole system is the main damper to control pitch. There is no torsion bar controlling roll, just the antiroll bar, which is the T shaped component mounted at the front via the two pillow blocks (an anti roll bar is in esance a torsion bar though i guess!)

furnik28 · Post 05 Jul 2006, 09:41

this is not what the first thread ment look at the arrow pointing to the top wishbone there is abar going west and east that tha anti intrusion bar. stop assuming this or that look at photo up and

close

zac510 · Post 05 Jul 2006, 10:56

furnik, that question has already been answered.

luisandregg, it must be!

Powerslide · Post 01 Aug 2006, 21:21

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