Alright guys,

Had a look at the rear beam today with the intention of stiffening it up, my front set-up consists of a stage 2 frame, arb blocks, full polybushing and uprated shocks and springs which is making the rear feel very soft and sloppy.

I had the car jacked up so both rear wheels were off the ground and the amount you can twist the beam is stupid! , so I'm thinking about either a custom arb setup, braces from the stub axle mounts to the beam itself to create a triangle or a single brace from one stubaxle to the other.

Anyone done any of these? Or is there any other better methods of stiffening it up?

Rover 200 coupe arb

http://www.clubpolo.co.uk/forum/index.php?showtopic=215284

Edited 9 July, 201115 yr by 01mlacey

Nice,

Anyone with bracing?

seen on golfs that are similar design...people box in the main beam part , so where its a L shape use a plate to box it , sposed to stiffen it up

seen on golfs that are similar design...people box in the main beam part , so where its a L shape use a plate to box it , sposed to stiffen it up

guy on here welded a plate in the corner for extra stiffness and strenth

what about g40 rear axle max? mena be loads stiff and has arb on it standard i heard

Yeah that's what I had in mind. Gonna take a look at it tomorrow, there's a lot of room for improvement though!

thing is if you stiffen it by boxing the L shape bit , i recon it will try and twist elsewhere in a more concentrated area and maybe crack ?

not that I'm an engineer lol , just needs thinking about a bit

Yeah its gonna have to be done properly.

I think I'm gonna go for either a rear arb which will just help prevent the legs from twisting when cornering,

Or some sort of subframe that will bolt onto the cross member part of the beam, and then bolts to legs, creating a triangle which will stiffen everything up and eliminate twist.

What ever you do I'm sure it will do good max

hows the stage 2 subframe ? was there a massive differance then with tht bad boy on..

To be quite honest I can't tell the difference , the biggest improvement I noticed was when I first put the arb blocks on. They make a huge difference. The subframe may come into play when she gets a blast on the track.

To be quite honest I can't tell the difference , the biggest improvement I noticed was when I first put the arb blocks on. They make a huge difference. The subframe may come into play when she gets a blast on the track.

Oh really..

to fair for the price i would have expexted a very big difference

but like you say prob wont come in to play untill you drash it into corners

If you want a major difference then the stage 3 is more the answer, but you should have noticed some difference, back bar pre-tensioned properly?

get a rsj and cable tie it on your beam it works great my back wheel is never on the ground

How about a rear upper brace? Rear poly bushes?

Yeah a rear upper brace may work, but I'm talking about rear beam stiffness not chassis.

And polybushing the beam won't get rid of the flex :( :(

But how do you know it's just the beam causing the poor handling at the rear; because you can twist it by hand? There's likely to be flex in many areas.

To stiffen up, you could weld a piece of angle inside the angle of the rear axle, essentially doubling the thickness of the metal there. The danger is making it too stiff though, and having one of the wheels cocked at the mere sight of a bend. Personally I'd use a g40/gt beam with polybushes and upper brace (between the turrets not those budget ones that are bolted to the shock) to start with. They are all fairly simple, and can be removed if you find it's too stiff. If it's still too wobbly, then i'd start welding plates and braces onto the beam since these will be more hassle to remove if you screw it

what about something like this...

Mk1 hillclimb spec rear axle

Edited 10 July, 201115 yr by pettsy

There are various bolt-on ARB's, I've replaced my old bulky and complicated Rover 200 ARB with a simple directly bolted-on item from a Skoda Felicia.

Got pics on my phone but the screen's smashed, will update above linked topic when i replace the screen.

Cool. Post some pics up on here too!

This topic is more relevant to the subject.

are you sure it's not just knackered axle bushes?

No. Its the actual beam that's just very easy to bend. Nothings wrong with it though as both other 86c polo's i checked had the same story. Just seem very easy to flex.

Being a track wizard hayesy, have you not found room for improvement?

What is your current rear suspension? There's nothing wrong with the beam flexing across it's width but control it with the suspension, don't stop it working. The more spring you have, the less you should need an arb. A common problem is that the shock travel is too much. If it was limited by shortening the shock or have a droop limiter, you would lift the inner wheel which has the effect of reducing the roll. A brilliant example of this is shown in the vids of

. Watch the rear wheel at the first hairpin. There's only a couple on inches of total travel. Upper braces don't really do anything. Tie some cotton thread between yours and go for a drive. If you manage to snap it then there's some movement but it's only affecting the damping slightly and has no effect on the geometry. I have one because it stops boxes moving around the boot and I can ti-wrap things to it. The bars shown the axle photo above stop camber change and impact damage to the beam.

Here's a seat works rear beam. The arms are mounted on bearings and rotate freely relative to each other. The arb is mounted through the shell and acts directly above the stub axle.

That helped alot cheers!

The current suspension set-up consists of uprated shocks and sprins which have probably lowered the car by about -70mm.

I don't want to stop it working obviously, but try and improve it. There isn't much shock travel at all at the moment aswell.

Stick some ta mk1 golf rear coilies on it if you wanna stiffen up the rear

Stick some ta mk1 golf rear coilies on it if you wanna stiffen up the rear

Trust me the springs and shocks are pretty stiff already, i can feel every little stone i go over, but its in the corners where the rear just seems all over the place compared to the front!