Wishbones

[Cameron 16]

Just to help you along, the wishbones will experience their highest loading under braking and actually get relatively little loading from bump loads such as driving over a pothole or speed bump. The next highest loads will come from cornering.

 

If you want any help with this I can run some FEA sims on them to see how well they would cope and what your safety factor is. I'd only need an IGES file of your design.

[Mandic 0]

But then, I designed mine to cope with rallying or whacking a banking side on - they've got a shear pin that'll bend/break before the tube or subframe buckles to take the energy out.

 

Can shear pin be bought or did You make it?

 

Thanks!

 

Ziga

[Rippthrough 98]

Made it - just a capscrew with a pair of machined notches so it breaks at a specific force.

[Mandic 0]

Thought so, thanks!

 

Ziga

[wracing 19]

The reason I said bump forces been the highest is that im from a caterham background certain geometries + harsh curb = bent wishbone. i have yet to do the calcs on a 205

 

Im almost of the opinion that the originals are so feeble then anything must be better does anyone have a st of the compbrake wishbones? what material are they made from.

 

Im very tempted to remove the bend from the wish bone, I assume this has been put in by peugeot on standard suspension so the ball joint is offered up at 90 degrees to the pin hole, due to the fact most 205s are lowered to some degree (not rally cars) surely that would negate the point of the bend. What's you opinion guys??

 

Thanks

 

James

[Cameron 16]

Sounds about right on the balljoint front, but I think it would be best to keep the bend in. A lot of people will be running near standard ride height (such as the rally cars) and those that are lowered quite a lot won't have any more bump travel than normal.

 

The Caterham wishbones are easy to bend because their shock arrangement puts the wishbone in bending. 205's using McPherson struts won't be putting those loads in the wishbones, it'll be mainly tension and compression, but you will get bending under braking caused by the Y-shape.

[wracing 19]

I know I did some analysis on the 'book' wishbones that I was running. As soon as the simulation had finished, I was taking them off my car! Horrific design, would bend in the same place every time and turned out to have a safety factor 1.something, far to low for a suspension component!!

 

I'm just thinking out loud my wishbones at present sit dead level. I may have to get hold of a standard 205, and see if I can use a straight wishbone, as to me the standard bend is the wrong way (as in it offers not strength) and a possible route cause for a large bend to form in a failure situation. The 306 balljoint has a higher degree of articulation and the 306 wishbone has no crank so im unsure.

 

Thanks

 

James

[welshpug 1,645]

the crank is in the 306 balljoint rather than the wishbone.

[wracing 19]

im off back to work not so ill have a better look at the 306

[Rippthrough 98]

Bend is in the balljoint on the 306:

 

[Cameron 16]

You're right actually, I think the majority of 205's these will go on would benefit from removing the bend and having straight wishbones.

 

Ripthrough is that a fancy ARB drop-link on that 306?

[Pug_Power_Dave 0]

Those ideas look pretty cool! Recon everybody will have a pair at that price lol!

 

Is it the 16 or 18mm 306 ball joint you need to fit on the 205 hub?

 

Cheers

Dave

[tri_longer 25]

Ripthrough is that a fancy ARB drop-link on that 306?

 

Speaking of which, given the nature of the 205 ARB, are there any options to upgarding the 205 droplinks to something similar.

 

Or would this require a new ARB fabricating with the bolt holes for the droplink turning through 90 degrees, or could you use a 306 ARB?

[Rippthrough 98]

You're right actually, I think the majority of 205's these will go on would benefit from removing the bend and having straight wishbones.

 

Ripthrough is that a fancy ARB drop-link on that 306?

 

That's an old one, they're fancier now:

 

 

 

Tri - simple solution:

 

 

We've wandered off-topic a bit

Edited May 5, 2010 by Rippthrough

[tri_longer 25]

We've wandered off-topic a bit

 

Sorry, my fault.

[welshpug 1,645]

entirely on topic IMO

[Cameron 16]

How are those made? They look like alloy billet / bar stock.

 

Would be good to look into making new front ARB's that can use the original mounts but have a different shape so that proper V-shaped wishbones can be used! I think that might be a good project for someone this summer.

[Rippthrough 98]

How are those made? They look like alloy billet / bar stock.

 

Turned down and milled from inch round billet.

 

Would be good to look into making new front ARB's that can use the original mounts but have a different shape so that proper V-shaped wishbones can be used! I think that might be a good project for someone this summer.

 

Working on it

[Cameron 16]

Good man.

 

Isn't that a bit excessive though? Surely you could save more weight and a bit of machining time by having thin walled steel and machined threaded plugs?

[M_R_205 5 1 Cars]

You need to keep the bend in the wishbone otherwise the wishbone will foul on the hub its self, i found this out after i welded a pair of wishbones to accept a rose joint, machined some pins for the hub to sit on, bolted everything up and realised the error of my way! and this was on a lowered car, if you look at the hub, with the shock in a 90* position, the ball joint clamp would be at about 115/120 degrees....

 

Paul.

 

EDIT

Would be good to look into making new front ARB's that can use the original mounts but have a different shape so that proper V-shaped wishbones can be used! I think that might be a good project for someone this summer

 

This would be a very good idea but you would have to either mount the ARB above or below the wishbone as simpily widening it will make the rear edge of the tyre hit the ARB..

Edited May 5, 2010 by M_R_205

[wracing 19]

Happy days that makes life alot easier no bend then it is. I've been chatting with the company that does my laser cutting. Its looking like we have a very good chance of coming in on budget of 80 pounds per pair @ 12mm thick (dependant on results)

 

Im planning on using the balljoint mounting holes as fixings to the jig. I cant decided if to use a thick walled seamed tubing for the inboard bushes, and make sure that the seam is between the 2 welds if that makes sense. Or use bar with a hole bored through.

 

Thanks

 

James

[wracing 19]

mr205, do you think that we should be able to use the crank on the 306 ball joint, ive had a quick look at for and it comes very close to the 205 wishbone. meaning no bend in the wishbone

 

Thanks

 

James

[M_R_205 5 1 Cars]

Im planning on using the balljoint mounting holes as fixings to the jig. I cant decided if to use a thick walled seamed tubing for the inboard bushes, and make sure that the seam is between the 2 welds if that makes sense. Or use bar with a hole bored through.

 

Thanks

 

James

 

Im planning on fitting standard mounts to my comp brake wishbones and iv was advised to used hollowed out bar as a apposed to seamed tube, however alot of the locost cars use the latter technique but being much lighter have less stress, and its cheaper...

 

Paul

 

EDIT agin

 

mr205, do you think that we should be able to use the crank on the 306 ball joint, ive had a quick look at for and it comes very close to the 205 wishbone. meaning no bend in the wishbone unsure.gif

 

Thanks

 

James

 

Im afraid i would only be guessing if i answed that, il dig out my wishbones and a hub, and send you a pic of how badly the fouled...

 

paul.

Edited May 5, 2010 by M_R_205

[wracing 19]

Ok thanks, If i can get these right first time then it will make my life very easy!!

 

While I can see a failure point with the seamed tube I don't see if its between to welds how it can ever be loaded to a point where it would fail.

 

Thanks

 

James

[Cameron 16]

Why not use CDS tube?

 

Also RE: the anti-roll bar, it wouldn't be as simple as just relaxing one bend, the whole thing would need to be redesigned. I'm sure it can be worked around very easily though.