New Front Wishbones

[squiglyzigly]

I also made the alloy pedestal spacers to sit under the lower ball joints.
My reasoning for these was to bring the wishbones back down to their correct operational arc. Obviously, when you keep lowering the car from its original high rise factory suspension design, the wishbones no longer ‘bump’ into negative camber when cornering hard (instead they introduce positive camber) and conversely they also introduce unwanted camber changes when accelerating hard.
I find these pedestals improve all areas of grip from cornering, traction and braking to stability over surface changes and less torque steer. Cheap and easy to make. 

[squiglyzigly]

Strengthing wise for the front end, I opted to make a pair of braces that link from the area at the bottom of the suspension turrets (where the chassis rail runs horizontally) to the subframe. Thereby closing the flexing gape between the weight of the power train sitting on the subframe and the car being lifted at the top of the turrets. There is also a diagonal welded from the chassis rail next to the turret top, extending down to the lower door hinge area.

[squiglyzigly]

Strengthening work

[mangocrazy]

Wow - two for the price of one...! Those custom wishbones look fantastic, Eric. Did GB Engineering fabricate those for you? I suspect the price is too rich for my blood, but that should completely cure any flex in that area.

I very much like your bracing mods to the standard wishbones, SZ. I think I'm definitely going to copy that. I can see you ride bikes as well (another Aprilia owner here), and that mod reminds me somewhat of bracing work that Tony Foale did for Tony Middlehurst (Superbike magazine Editor in the 80s) to a (pre-ZXR) Kawasaki 750 that was suffering bendy frame syndrome. Did you use standard mild steel tube or something more exotic?

The ball joint risers intrigue me as well. I've got a pair of lowering (shorter) springs for the front of the car that will go on eventually. But would that mod work equally well on a standard ride height Beta? What thickness of aliuminium plate did you use for them, and did you make them yourself or get them fabbed up?

I like the other strengthening mods as well, but I'm not sure about welding bits into the bodywork. Perhaps once all the other stuff is done.

[squiglyzigly]

The wishbone strengthening is light guage steel tubing as its only additional stiffness rather than complete load bearing.
The alloy pedestal risers are 20mm and hand made.

[WestonE]

Really Interesting input and clever work. I need to think about the additional subframe to body bracing fairly rapidly to have mounts built onto the shell and subframe. The ball joint spacers are an interesting idea and one I have never tried. I think I will try a back to back comparison when the car is running as I have Gasmatic Gold Coil overs all round.

I notice the change of front calliper to what looks like a Ford item?

I have 6 Piston Callipers built up for Integrale 284 front discs and will be finding out if my design works in due course.

The Wishbones were made by Amtech Fabrications in Wooburn Green, but I have the build jig as part of the development cost. Amtech designed and make the chassis for Stratos Replicas sold by one of the big kit car names and definitely bring some suspension design skill to the game.

Eric       

[squiglyzigly]

Hi Eric,
I take no credit for the chassis strengthening idea to strap the subframe to the chassis rail above. It had bugged me for years as to how much flex there must be in this area, but the push to do something about it came when I realised several more modern cars had already done just that.
The alloy pedestal spacers under the lower ball joint was an idea I came up with when running a race car about as low as it could go. Have a try and see what you think. Its a simple mod to put in place using different thickness pedestals and equally simple to remove if you prefer the feel without.
The brakes are Fiat Croma turbo/early Thema turbo (14 inch wheel models). From memory they are only 257mm, so they will not match the power of your 6 pot setup on 'grale discs. I opted to go the early Croma/Thema route as they fit inside the original 14 inch beta alloys if required.
As I'm sure you know, when you go away from the beta front discs, you loose the wheel central locating hub. I overcame this by simply fitting Thema hub flanges into the original beta hub carriers and wheel bearings. All interchangeable. Just an adapter bracket to mount the brake caliper carrier was all that was needed to complete the install.

I look forward to seeing your next monster Beta project, do you have a timeframe for road testing?

[mangocrazy]

As I'm sure you know, when you go away from the beta front discs, you loose the wheel central locating hub. I overcame this by simply fitting Thema hub flanges into the original beta hub carriers and wheel bearings. All interchangeable. Just an adapter bracket to mount the brake caliper carrier was all that was needed to complete the install.

Yes, I laboriously figured that out, as I'm in the process of upgrading the brakes on my spider to 4 pot calipers (originally owned by Eric before he went to 6-pot calipers) using the readily available 284mm ventilated discs. This means I have to go to 15 inch wheels for internal clearance and, as you say, compensate for the loss of the Beta locating hub. I'm using a Thema 16v i.e. hub (early version). The later versions have a larger diameter spline and aren't interchangeable with Beta hardware. I only found this out by ordering the wrong part initially...

[mangocrazy]

Cross braced standard wishbones with particular strengthening along the sides either side of the lower ball joint mounting holes (circled) as I found this the main area of flex. Obvious I guess as it’s the ‘single’ most loaded area of the wishbone trying to transfer torque to the two bushes.

Hi Ian,

Could you expand further on how you beefed up the area of the wishbone closest to the ball joint mounting holes? I can't really make out the detail of your modifications in the photo. What metal did you add and where?

Cheers, Graham

[squiglyzigly]

Hi Graham,
I'll get down to my Dads this week (where I keep the car) and take a picture for posting.

All the best,
Ian

[mangocrazy]

Excellent! Many thanks, Graham

[mangocrazy]

I'm gradually working my way through the steps needed to upgrade the brakes on the Spider, and one of the ever-expanding knock on effects is that new hubs will be required. As I really don't want to be faffing about in France with minimal access to special tools and specialist services, I'm intending to take a whole bunch of stuff down with me and just swap it out. As a result, I acquired a pair of front uprights (and fortuitously) a pair of front wishbones from Peter (peteracs of this parish) to prepare for the task, rather than doing battle with the ones currently fitted to the car.

Ian (squiglyzigly) has further made me realise that I need a set of braced front wishbones in my life (and on the car), and so Peter's donations are to be pressed into service for this. I didn't take any 'before' photos, but Peter will confirm that none of the items were exactly in pristine condition, particularly the wishbones. I'd eventually managed to remove the hubs, bearing retainers and bearings from the uprights (although not without a proper fight) and also remove a particularly stubborn ball joint from the wishbone. The last part  of the work was to remove the old rubber bushes. A Rothenberger Superfire 2 plumbing torch with a MAPP gas canister attached accomplished that in a particularly satisfying manner.

So the next step was to dump the rusty uprights and wishbones in the citric acid tank I have. This is a 15 gallon/68 litre plastic cold water tank and lid (very important), with an aquarium heater immersed in the solution to speed up the process. I left the parts stewing in the tank overnight in the shed, with the tank seated on 3 layers of polystyrene to reduce heat loss through the concrete floor.

As you can see from the pics below, there are still some parts that will need blasting, mainly where old paint or underseal has adhered to the surface, but the results are way better than I had any hopes of achieving. The uprights in particular will only need a light blow over with the vapour blaster to make sure the threads are completely clear and they will be ready for phosphating. The wishbones will be media blasted and then braced in the way that Ian has demonstrated and finally zinc plated (I think). So all in all, a bit of a result.

[squiglyzigly]

Hi Graham,
here's the area worth reinforcing hightlighted in red. Its worth welding a fillet on both forward and rear facing outer faces in this area to prevent and flex around the lower ball joint mounting. I usually use steel guage similar to the wishbone itself.

Hope this helps

Ian

[mangocrazy]

Hi Ian, yes that makes sense. You're basically triangulating that area (front and back sides) to strengthen it, as far as I can see. Obviously it mustn't interfere with any suspension movement, but I imagine you can get a good increase in rigidity without adding too much metal.

Cheers!

Graham

[rachaeljf]

Eric, how much will two pairs of your wishbones cost?

Thanks Rachael

[WestonE]

Hi Rachel

At the moment I am not sure I need to ask the firm that made mine and price up the bushes.

I am also very busy with work so bear with me

Eric 

[rachaeljf]

No worries, many thanks.

[mangocrazy]

The uprights and new Thema hubs went off to be phosphated a couple of weeks ago (after being vapour blasted) and when they came back were taken to a local engineering shop to have the (NOS) bearings pressed into the uprights and the hubs pressed into the bearing inners.

I'm very pleased with the phosphate finish; it looks smart and should provide a good degree of corrosion resistance. Phosphating is a proper surface treatment, in that it alters the chemical structure of the surface layer of the steel but with only the tiniest amount of dimensional change (fractions of a micron) - important when bearing surfaces are involved. It's also an excellent base layer for subsequent powder coating, should you choose to do so. Here's a couple of photos of how they look now: