rear anti roll bar...why is it there?

I'm in the process of refurbishing the rear axle on my mark 1 Golf. I have got to the anti roll bar, which is mounted on the rear beam with four rubber mounting points. Ii doesn't attach to the body anywhere but is strapped along the rear beam and the two welded tubes that carry the rear wheels. There should be no relative movement in the beam and two axles tubes as it is a welded single unit therefore I doesn't see how the roll bar could possibly function as it is fastened all along the beam and tubes where there should be no relative movement. unless the angle iron beam is supposed to act as a torsion bar. Is this perhaps what is supposed to happen?  If this is so, it is not a true anti roll bar at all and the same  result could be produced by making the beam section slightly larger and dispensing with the so called anti roll bar, which would have been a much cheaper option for VW. Any help and comments would be welcome

 

Hi there, and welcome to this great forum.
I think you've answered your own question to be fair.  I'm sure the boffins at VW knew what they were doing, and why.
I have just finished refurbing mine with new bushes and a reconditioned anti roll bar from crazyquiffs. My god, it's a heavy piece of kit😀

I guess when first introduced no anti roll bars were fitted and while looking at some early film of the mk1 golf they do have some body roll. Then when bigger faster engines started being fitted it was cheaper to fit an additional item, ie the antiroll bar than re producing another rear beam when they already had one..

The Golf was only meant to be a family car then some engineers worked on their own and made the GTi , the rest the history  

The rear is a torsion beam (which is basically a big sway bar itself) the bar makes the entire beam stiffer, limiting roll. This design cannot be connected to the body or you'll create a rigid mounted rear which is no longer effective at anything except killing your back and crashing your car.

(typically) To make a front wheel drive car turn in better you need to stiffen the rear, or inversly loosen the front. Depending on your driving skill, leave the rear anit roll bar alone and disconnect the front. The car will turn in better.

I don't run any sway bars at all, started out as a CL model so none were installed. I have 36 way adjustable coilovers with custom spring rates, stiffer spring rates in the rear.

The rear beam also pivots on the factory rubber bushings this causes the outside tire to toe out helping the car to turn in, also causing the legendary inside tire lifting off the ground. Installing poly bushings in the rear beam stops this from functioning and causes the car to push in corners.

I run poly everywhere else, even the steering rack. The car rides very nice turns well, very neutral.

If you get your setup wrong it can cause the rear to come around on you in hard cornering, so if you're not well versed on the subject I'd recommend sticking to the factory setup, or an aftermarket kit.