How Not To Modify Your 205's Suspension...

[Henry 1.9GTi 36]

The standard arb mounts were poly but disconnected the arb and made no difference. The wishbones are new not so long ago OE peugeot 309 and were completely free when I fitted the suspension. The CV joints are again new OE pug. The drop links are new items and free to move and the track rod ends are free. The top mount spherical was free when off the car. Hopefully the dyno will tell me whether or not the dampers are at fault but will be a while before I do that. Engine doesn't run at the moment so in no rush

[Cameron 16]

Well whatever's causing it, 45kg is a hell of a lot of stiction! The only thing I can think of other than sticky damper seals / bushes is the new bottom ball joints but I really can't see them causing anywhere near that much.

 

As you say getting the dampers on the dyno isn't going to prove that much as you're only subjecting them to axial loading. If you can figure out a way to load them across the axis at the same time (i.e. how they're loaded on the car) then that may well show a difference. It would make sense that if the bushes are at fault then the extra camber from your 309 wishbones and top mounts will be putting a higher bend load on the dampers.

Edited January 29, 2011 by Cameron

[Henry 1.9GTi 36]

yeh the plan is to see what the dyno has to say and if all is well to make up some custom spring pans to run the springs at the maximum angle allowable by thier ID to get the spring more inline with the kingpin axis. I'm really hope if I'm nice to my lecturer and I manage to get some work done on the car! that i can get it back on the rig to measure any differences.

 

Could you please send me those hardpoints and a brief spec of your geometry like wishbone type trailing arms etc... got a roll angle and weight trans calc which accounts for RC unsprung mass CoG height etc... and seeing as the 205 has pretty much zero camber compensation it gives a good indication of the static camber needed for different spring rates and G-Force its a matlab file if you want it I can send your way.

Cheers.

[kyepan 291]

a quick reply to this post...

 

so the car is now running standard ride height, standard toe, and is behaving very well, need to take it on some bumpier lanes, once the misfire is sorted out.

 

cheers

 

j

[Cameron 16]

I created a calculator in Excel, mainly because I hate using matlab. But yeah send it over please and I'll have a play.

 

I'll send you the HP's tonight, just send me a PM with your email address and I'll send the points in an xls file.

[Henry 1.9GTi 36]

Sorry kyepan, i'll start a sepeate topic after the dyno session to keep this one more on topic!

 

Henry.

[Cameron 16]

I think this discussion is still very relevant though.

[kyepan 291]

a quick report, now...

 

Inital feedback following toe adjustment are

 

Standard toe 0.6 deg toe in

 

All of the bad behaviour seems to have disappeared, tram-lining grabbing, going with the camber, power understeer straight across the road..

This actually surprised me more than i was expecting.

 

The falkens on the front have yet to bed in and i am finding myself lacking front end grip. any more than neutral throttle on damp and slippy bits gives wanton power understeer.

 

one dry properly dry corner the other day and you could steer it on the diff coming out of the turn, but that was one corner.

 

The feeling of the back end worries me, especially on negative camber right handers, where it feels like it wants to step out, i am going to double check the tyre pressures.

 

The general damping rates got wound up recently, i'm going to slacken them off too as i feel it's a touch over damped.

 

Need some decently dry days above ten degrees when the chemical salt has been washed off the roads to give it a good bash. Cameron, why not come to the next curry meet and we can do some measurements..

[Cameron 16]

Yeah I keep meaning to come to one but they always seem to pop up alongside birthdays etc. I'll keep any eye out for dates.

[engine killer 5]

Another fail after my second attempt. The steel is TOO WEAK! It bent!

 

 

Both arms pointing downward nicely as expected

 

 

unfortunately they bent after a few miles test run (fortunately only a very few miles)

 

 

So now back to original. Somehow I have my revised bumpsteer kit installed, it improves by a huge amount. Much much more stable even when over 100mph, only a very very little bumpsteer.

 

I will have a new roll centre kit fabricated soon by another workshop (more reputable). This time I will either have it done in a stronger material or welded to the hub.

Edited April 26, 2011 by engine killer

[kubas 0]

Hi Guys.

 

My current suspension setup is:

 

wheels:

 

106 rallye michelin steelies 6inches + toyo r888 185/60/14

 

front:

 

309 wishbones + poly

309 arb

kyb agx

some spring 40mm lower than standard

 

rear

205xs rear beam

205gti 19mm ARB

 

Got some problems with understeer. This week I will change front 309arb for 205gti standard arb.

And I'm looking for 24mm rear arb from 106gti + partner torrsion bars 21.3 but It's hard to buy it in Poland.

 

These are pictures of my front suspension setup. I'm wondering if the whisbone's position is ok? Or can it go for postive camber on track ?

 

 

[Cameron 16]

Get a new set of tyres for a start, that won't be helping!

[kubas 0]

Tyres are perfect There is some problem with toyo tyres in Poland right now... Every shop is out of stock...

 

Cameron what obout whisbones position ? Is it ok ?

[Cameron 16]

It isn't ideal, but mine is probably a bit lower than that! I run 3 degrees of static camber to make up for it which helps a lot.

 

We have similar problems in the UK with Yokohama A048's, they just can't seem to make enough of them!

[B1ack_Mi16 67]

It will bend due to the bending moment it has to transfer through that very small diameter tap.

 

If you could bore out the hubs slightly to make room for a larger tap, and at the same time somehow be able to pre-tension the tap to the hub the bending will be taken more by contact between the flat surface on the balljoint spacer and the bottom of the hub.

 

However I believe that using a 406 hub carrier is the way forward. M40x1.5 threads to fit the spacer in.

 

I have bought the steel for machining these spacers myself. I'm not sure I will dare to make them any longer than 30mm though due to the bending moment that now need to be transfered through the threads.

 

 

Another fail after my second attempt. The steel is TOO WEAK! It bent!

 

 

Both arms pointing downward nicely as expected

 

 

unfortunately they bent after a few miles test run (fortunately only a very few miles)

 

 

So now back to original. Somehow I have my revised bumpsteer kit installed, it improves by a huge amount. Much much more stable even when over 100mph, only a very very little bumpsteer.

 

I will have a new roll centre kit fabricated soon by another workshop (more reputable). This time I will either have it done in a stronger material or welded to the hub.

[engine killer 5]

This is from an ex-WTCC car. They have the hub carrier reinforced by loads of welding.

 

By just looking at it, the spacer is seems held by the high tensile screw.

[B1ack_Mi16 67]

Something like that I ment, as the pinch bolt seem to be fastened by a nut on the top which makes it all more rigid.

But I think you'll run into clearance problems with the CV joint.

[engine killer 5]

Something like that I ment, as the pinch bolt seem to be fastened by a nut on the top which makes it all more rigid.

But I think you'll run into clearance problems with the CV joint.

 

 

IIRC the clearance is just about 10mm, so even if we use a bolt instead of nut there will still face the clearance problem or almost touching.

 

If you look at my second attempt (the pict that shown how it failed), the clamping side seems perfect by the joining bent.

 

My third will be using the 2nd failed one welded to the carrier. The top and the joint of 4 sides will all be welded together plus a lot of reinforcing pieces (shall I call it web) joining from about an inch above the original clamping down to the bottom of the spacer to strengthen the clamp pick-up.

 

hmmm, I am out of vocab so will post pictures instead later.

[welshpug 1,621]

http://www.citroenpartsdirect.com/app/webroot/userfiles/files/E12.pdf

 

http://www.citroenpartsdirect.com/app/webroot/userfiles/files/E13.pdf

[B1ack_Mi16 67]

That is quite clever, but I doubt there is enough meat in the 309 wishbones to make threads for the balljoint in the wishbone itself.

Also it ideally need to be extended by 2cm ish to compensate for the different balljoint offset between the 205 and 405 hub.

[engine killer 5]

That is quite clever, but I doubt there is enough meat in the 309 wishbones to make threads for the balljoint in the wishbone itself.

Also it ideally need to be extended by 2cm ish to compensate for the different balljoint offset between the 205 and 405 hub.

 

I saw the Nissan S14 has similar design, you can also get the extended balljoint from aftermarket.

 

http://www.frsport.com/Megan-Racing-MR-6387-Front-Roll-Center-Adjuster-Nissan-240SX-S14-95-98_p_15421.html

 

so if any one want to modify their wishbones to this design, should consider to use something else other than PSA.

[engine killer 5]

My third attempt is about to be tested in February.

 

Here are some picts for your comment. It is now welded to the hub carrier with web reinforcement welded to it.

 

 

 

 

[B1ack_Mi16 67]

Was it easy enought to weld the carriers? Ain't those cast iron?

[Cameron 16]

I'm becoming less and less convinced that the roll centre needs to be raised at all.. it's bump steer that's the enemy with lowering the front, and while having the roll centre low causes more body roll, fitting thicker springs and ARB to the rear basically resets this and helps the front end out at the same time by taking up some of the load transfer.

 

Ok so you lose out on camber compensation having the wishbone at the "wrong" angle, but if your roll angles are low - as they are when you fit stiffer springs and ARB's - then are you losing out on much? I think by running a bit more static -ve camber you're solving that problem too. You certainly benefit from lowering the CG a lot more than changing roll centre heights.

[EdCherry 34 1 Cars]

Camber Compensation not an issue really, as your travel is pretty limited, or should be. Also getting enough Camber isn't an issue either.

 

I feel the only issues that needs sorting is getting the heat spread across the rear tyres and too much load transfer under braking to start off with.