Adjustable blade ARB's

[Jon441cc]

[Graham]

Not sure, but the coupe in the pic has a nice tasty Rear Diff oil cooler plummed in, do the bars work in conjunction with the ARB??

[BRY]

Anti-roll (sway) bar blade?

[Jon441cc]

Anti-roll (sway) bar blade?

Cheers Bry

[Jon441cc]

When you turn the blades you actually increase the profile of them (looking from the side). This will stiffen them - the higher the profile the stiffer it gets. The thinking behind a ARB like this is that the bar that goes from one side to the other is stiff. Stiff as can be. All of the deformation from bodyroll will be taken up by the "leaf" springs at the ends (the yellow bits). These ARB's are the most common setup in racing.

If you don't believe me try it your self... Take a ruler and then light it from the back, projecting the profile on a wall f.i. If you start where the ruler will just be a thin line and then turn the ruler along the length-axle you will see that the profile increases. The stiffness of a bar increases by the height of it! Easy-peasy...

Henka is right - those ARB arms are coming out at an angle from mountings in cylindrical bushes on the ends of the bar, and they are indeed blade adjusters!!! When I first looked at this picture I thought they were nearly parallel to the centreline of the ARB (that's what I was remarking on first time I posted), but they are probably about 60 degrees to the bar when viewed normal to the plane that intersects the arms.

You don't really need blades at both ends, that's just a nicety - we used them extensively in single seat cars and touring cars too - in fact, I've designed a few of these! As Henka says, the blade is softer when laid over flat, and stiffer when turned vertical, and varies between those two extremes.

I think a better analogy is to hold a steel rule halfway onto your table and bend it downwards - very easy when it's laid flat. Now stand the rule on edge and try pressing down on it. Much stiffer! The bar itself will be stiff, but will still work as a torsion bar, you set it up to the maximum possible stiffness you think you'll need. Then you use the blade adjuster to soften it.

We had cockpit adjustable versions on some cars, using a push-pull cable and a lever linkage similar to a throttle lever on the end of the blade adjuster. The touring cars had long cockpit levers (both ARBs were adjustable). I designed one for a single seater that had a push-pull cable which could also be fine adjusted by turning a knob on the end of the cable (Japanese FToyota). F3 also had cockpit adjuster but this had to be locked for qulifying and race, as it is illegal for anything other than testing (well, it was when I did F3!)

I'll have to have a dig in my drawing archives now!!!

__MDC__

Cheers Guys

[Jeffer]

Funny you bring this up. I've been working on a bolt on kit for our cars with these blade style ARB'S. Drawings are done in solidworks. Now its maching and fabricating the bar itself. I'll be using them front and rear, and will produce in series ready to bolt on to other s2's.

[5inline]

From my old 80 quattro

[Jon441cc]

From my old 80 quattro

Very nice set-up 5inline Have you got any detailed pics of the clamp on the blade ?

Ps Whats your name ?

Cheers Jon

[Jon441cc]

Funny you bring this up. I've been working on a bolt on kit for our cars with these blade style ARB'S. Drawings are done in solidworks. Now its maching and fabricating the bar itself. I'll be using them front and rear, and will produce in series ready to bolt on to other s2's.

Any updates

[Jeffer]

Some updates
I took measurements of My SQ suspension on the car. That way I had some dimensions to work to. This is what i came up with so far.
I've designed 2 brackets to be mounted on the subframe to hold the bar. This is a sketch, but with "defenite" sizes. I'm thinking of making a needle bearing in it, or something that will help it twist the bar easily in there. I'll be using 30 x 2 chromo tubing for the bar assembly.

[Jeffer]

with countersunk holes for allen bolts

[Jeffer]

Then we have the arm. This is also a definte size. The ring at the end is to keep it in place with an M8 bolt through it. In the front is a hole M8 to mount Heim joints to. The arm will be slid in the same 30 x 2 Chromo tube.
Perhaps i'll weld some tabs on it to convert it to adjustable in the car while driving. That would be an awesome feature.

[Jon441cc]

Can the title of this thread be changed. Maybe to '' Adjustable blade ARB's ''

Cheers

[Fat Audi 80]

Title changed as requested.

Cheers,

Steve.

[Jon441cc]

Title changed as requested.

Cheers,

Steve.

Wadda guy!

Cheers Steve

Jon