124 CSA Front suspension

Non-engine, eg: aerodynamics, gearboxes, brakes, suspension
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mickwood
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124 CSA Front suspension

Post by mickwood » Thu Mar 10, 2011 6:16 pm

Have moved this topic here as i think it is better located in the "forum" rather than as part of "sale and wanted"

Essentially the front suspension geometry of CSA is very different from CS1 Firstly the engine crossmember is different insofar as the outer end (to which the lower suspension pivot is attached) is set slightly further outboard than on CS1 See below
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The lower suspension pivots are steel castings, and they locate the lower suspension pivot much further outboard than on CS1 - this substantially changes the geometry. The outer end of the lower arm is then bolted to a compression strut (or brake reaction rod) which goes back and mounts just inboard of the chassis rails by the bulkhead. This effectively turns the unit into a wide based wishbone, but with the pivot line not parallel to the centreline of the car. it is significantly angled in to the rear. Again this substantially changes the dynamic geometry of the suspension as it goes through bump and rebound. The rear end of the compression strut is threaded, simplifying adjustment of caster angles. Camber is adjustred with shims as on the standard car.

The later works G4 cars also used a differnt casting which mounted the pivot cca 20mm lower. Again this changes geometry. They also experimented with a supplemental second damper.
here are some photos of suspension on my car (note the brake discs are non standard of my own fabrication. The calipers are 4 pot lockheed which were only fitted to works cars from 76 and never homologated!)
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here is another view taken without the discs fitted - (this is an earlier set up - note the inverted top wishbone to increase clearance from the wide wheels on full lock)
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here is photo of an unrestored final generation works car - note the extra protection for the lower damper mounts
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lastly here are the two types of suspension mount - the deeper one is the Group 4 part
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ace124
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Re: 124 CSA Front suspension

Post by ace124 » Thu Mar 10, 2011 9:51 pm

Mick Thanks for posting.
Any chance of getting those pix at full resolution?
My eyes are failing me.

mickwood
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Re: 124 CSA Front suspension

Post by mickwood » Fri Mar 11, 2011 6:22 pm

pictures at higher resolution (at request from guy) -
DSC01626_1.JPG
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DSC00169_1.JPG
DSC00169_1.JPG (111.57 KiB) Viewed 3282 times
DSC00170_1.JPG
DSC00170_1.JPG (110.34 KiB) Viewed 3282 times
DSC00171_1.JPG
DSC00171_1.JPG (114.04 KiB) Viewed 3282 times
IMG_3401_1.JPG
IMG_3401_1.JPG (175.53 KiB) Viewed 3282 times
IMG_3226_1.JPG
IMG_3226_1.JPG (167.85 KiB) Viewed 3282 times
DSC01614_1.JPG
DSC01614_1.JPG (81.27 KiB) Viewed 3282 times

Guy Croft
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Re: 124 CSA Front suspension

Post by Guy Croft » Sat Mar 12, 2011 9:50 am

MODEL POST!

Superbly illustrated with what are - really very rare photos. You might get few somewhere else but not that clean!

We are privileged to have you share your extraordinary 124 CSA knowledge and expertise Mick, thanks.

For those who don't know, Mick has been a Gp4 enthusiast for many years and has owned many of the marque and his knowledge of the setups (and the history of the cars and people who drove them) is pretty-well unrivalled.

G

brad131a4
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Re: 124 CSA Front suspension

Post by brad131a4 » Mon Mar 14, 2011 12:49 am

Yes very nice pictures. Mick I was wondering on the front stabilizer bar it looks that you are running it at a preloaded angle. Is this because of the running of the stock diameter bar or just from figuring it out by racing this works.
I'm guessing that no one has thought about re manufacturing these parts or making a copy of them? Would there be a patent problem if they were to be sold?
I could see making some of these out of 3/8 plate or 1/4. Now I guess I need to finish the other projects I have to get to this one.

mickwood
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Re: 124 CSA Front suspension

Post by mickwood » Mon Mar 14, 2011 12:51 pm

Not sure what you mean by "stabiliser bar". If you are referring to antiroll bar, then i can't see how you would pre-load, as it is full width and free to rotate in the front bushes. Yes it is loaded in these photos, but simply because the car is jacked up at one side.
As regards copy parts:
- Lower suspension arms are re-made in italy - either Stradale or Group 4 - made by the Abarth man who made them at the factory - not cheap, but i can give you contact. You can also get the inner bush
- Lower mounts come on the market occasionally, but always expensive - I guess you could fabricate to same pattern using sheet steel. If you want to do this i could send critical dimensions next week (i am travelling this week)
- Top wishbones on stradale are as CS1 - Group four version is merely reinforced (i can send photos next week)
- Compression strut could be remade by a good blacksmith, or spring manufacturer(to get the bend) and then a machine shop to get it threaded etc.
- You would need to replicate the pick up point on chassis. Bushes for rear mounting are still available
- Anti roll bar could be remade by any good spring manufacturer

If you need dimensions of anything - let me know.

brad131a4
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Re: 124 CSA Front suspension

Post by brad131a4 » Wed Mar 16, 2011 5:54 am

Yes you are correct on anti-rollbar. I see what you are saying with the preload. It would look like that with the other side of the car still on the ground.
About the only thing I don't have access to is a blacksmith but I know of a few farriers that might be able to bend the rod for me.
Dimensions to the front end parts would be great. I have the pictures but having to figure out the correct dimensions would add quite a bit of time. If it's not to much to ask Mick do you have the dimensions to the rear control arms for the abarth 124 also? If so could I get those to. If you could email me this info I would greatly appreciate it.

Brad

badlyworntoy

Re: 124 CSA Front suspension

Post by badlyworntoy » Sun Nov 06, 2011 9:53 am

Hi Mick
This Is my first post on here,I've been reading most of this forum over the last few months, as well as Guy's new book and one of his older ones trying to gen up on the Fiat/Lancia product. As its a marque I've never dabbled in before, other than a Delta HF Turbo I wasted years ago when I was a lad. I'd really appreciate some advice regarding the front suspension on the 124,as it looks very much like you know what your doing. I'm still assuming that the Lada Riva has the same front suspension as the Fiat 124, please correct me if I'm wrong?

I'm currently building a replica of the Lotus Lada and I actually want it to sit a bit lower than the origanal.I've being playng around chopping the springs trying to get it to sit where I want it,I've discovered that if you remove 4 coils front and rear You achive a drop of about 6 inches, this is where asthetically it looks the best.Now although on the back suspension this works ok the front has a few problems.The lower arms rake up at around 75 degrees and like wise with them the steering arms.They is also the issue of the dampers running out of travel.I'm not 100% sure what Lotus did with the suspension on that car but looking at the Info I have it looks like they've fitted Bilstein dampers at standard length and fitted spax springs,of length and poundage I don't know.

I was thinking of making some brackets similar to the works ones you have pictured here but making them to work with standard lower arms so that the arm mounts higher up the subframe,thus levelling the arm as close to 90 degrees as possible.Do you think this will work or can you see any other issues with doing this.I'm also going to make a spacer and delete the track rod end for a Rod end to lower the steering arm.I'm hoping then that I get some travel back on the dampers. If I dont then do you think it would be ok to make new lower damper bracket to mount them lower down in the arm? As i really dont want to get into Chassis and major suspension modification as I don't really have the time with this car to do this.

Sorry to just barge in here with a pile of questions I feel a bit cheeky.....Do you have any more pictures of your car,as Im always looking for ideas?
Many thanks in advance

Ian

ChrisSRT
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Re: 124 CSA Front suspension

Post by ChrisSRT » Sun Nov 06, 2011 11:55 am

when you flipped the uppercontrol arms it looks like you kept them on the same side of the car, which appears to have changed the caster quite a bit. Did it affect the handling much?
Chris
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mickwood
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Re: 124 CSA Front suspension

Post by mickwood » Mon Nov 07, 2011 7:02 pm

Brad. I think Lada front suspension was substantially similar to 124 saloon (which I think is substantially similar to 124 Spider, but not, of course, to CSA). I am a bit intrigued by the fact that you have lowered it so much that the bottom arm angles upward as much as you indicate. I presume that means you have minimal ground clearance if you run anything like a 530 dia tyre.
I would be very cautious about moving the inner lower pivot point as much as you are indicating without having somebody run it through a suspension geometry programme - my instinct is that what you are proposing will trigger quite major camber change through the range, going very negative on bump and positive on droop, with a consequent massive change in roll and handling over bumps.
You would also need to do something to raise the inner end of the track control arms if you want to avoid potentially catastrophic bump steer. One way to do that would be as you outline, through fabricating track arms with rose joints that allow for some adjustment in position through shims. I have some of these on the shelf. I will try to post a photo. Alternatively you caan get you local blacksmith to bend the Pitman arm on your steering box, and the idler arm
I am also a bit surprised that you mention the damper bottoming out due to lack of damper travel, as, on my car, the top wishbone will hit the turret before that happens (and that provides one very hard end to the range of suspension travel). However if you do have that problem, then fabricating a lower bottom mounting plate (or an adapter) shopuld be fine I think.


Chris - No. When I inverted the top wishbones I also swapped left for right. If you dont you would have a bucket load of negative caster.

badlyworntoy

Re: 124 CSA Front suspension

Post by badlyworntoy » Mon Nov 07, 2011 9:12 pm

Thanks Mick....sound advice!
They is around 5 inches ground clearence from the front crossmember and thats with 195/45/16 road tyres on and they is still around an inch between the top of the tyre and the edge of the front wheel arch.
I bought a Monroe Lada front shock absorber off an internet auction site and fitted it this evening and it seems to have alot more travel left than the ones which where on,could well have been the wrong ones but I'm glad as it seems to on the face of it to have sorted that issue out.It looks like they is a bump stop inside the piston cover reducing the travel.

Strangley enough the Camber has remained at -1 degree even with that mammouth 6 inch drop.Is they any reason why I couldn't simply shorten the bottom arm to maintain that sort of camber once they are remounted higher up the crossmember?

Can you recommend anyone who could work out how to modify the front the suspension for me and then set it up? I could jack it back up by 2 coils to around the height of the original Lotus lada but it just doesn't look right (In my opinion)and would therfore would really like to achive this mod.

Thanks again
Ian.

ChrisSRT
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Joined: Mon Dec 27, 2010 12:32 pm

Re: 124 CSA Front suspension

Post by ChrisSRT » Tue Nov 08, 2011 11:15 pm

Mick, thanks, I was looking at the track control arms so much, I missed the brake calipers.
Chris
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