ALFAGTV6.COM

[PietereQ]

Reading this topic has given me some thought regarding LCA mods. If I'm to build a well handling race gtv6 is it imperative to either go dropped spindles or upside down ball joint? With race ground clearance, the stock LCA points awfully upward, and I can't see that of any benefit to geometry. I have suspension lying around and maybe I just need a kick to do something about it. Well another delay with completion of the car... Btw Mike you mentioned that joint of yours was sourced of a holden gemini. Isn't it by chance what we Europeans call opel kadett c and the like? And what rims are you running in the Cab? I have 16" atm (and I wouldn't like to go beyond that), and even with the stock configuration, there seems to be little space between the rim and the wishbone.

[GTV27]

You don't need to run it so low that LCA's point upwards, even on the race track. By the time you run smaller OD race tyres (say 205/50 15, which is a common usage), it sits pretty damn low - low enough that clearance for a big pipe becomes marginal - or maybe our tracks are bumpier and spring rates lower than your's?

On the other hand, changing the upright for more dynamic camber gain might be a more useful modification....

[MD]

Hi Jason & Peter,

Lowering these cars particularly brings a lot of problems. Can't get them on the hoist. Damage on trailers when taking them off/on. Have to use special low jacks.. This time I haven't lowered the car as much as the previous race car.

I prefer the upside down ball joint configuration as I don't like the idea of welding the upright even though others do the opposite without apparent problems.

Peter, I dont know the European equivalent of the Gemini as I understood it was an all Japanese product carrying a GM badge locally. If it the Kadett has an upside down ball joint, well, it should do the job. I stress that you must have 16" rims to do this but since you want bigger brakes, all this works in your favour. When fitted up correctly, the clearance is about 10mm which is all you need.

I do not use Alfa stud pattern rims. My hubs are modified so I can chose from a whole range of wheel makes that are a lot more common. My PCD is 114.3

[scott.venables]

Hi MD. Did you re-drill the standard hubs? I'd like to do this for a friends race car. What did you do with the rear hubs? I was thinking ream the existing holes, press in inserts then re-drill on the 114.3 PCD. Front hubs are more straight forward.

Scott

[MD]

Hi Scott

Yes did the weld up and redrill scenario before but this time used a 12mm air craft spec aluminiun conversion plate. To claw back some offset, using 50+ve wheels.

[PietereQ]

It appears kadett c and gemini and dozen others are basically the same cars all based on GM-t platform. Reason I was asking is if this solution works (in your case it is) then why reinvent the wheel? Of course if it's ok with you sharing your tinkering. This is kadett c balljoint. Does this ring any bell?

[Giuliettaevo2]

The size off the pressed in part of the kadett balljoint is too small... You will need a ring that goes between the balljoint and the LCA.

I also looked into this for my own car but haven't found any good balljoint yet. It's a shame you can't really get any decent info on balljoints, most sites only carry a picture not a drawing with sizes. I looked at our local carparts-store in a few boxes but have had no luck finding a decent sized balljoint.

You also have to look at the way it's used in it's original application. The BMW E30 for instance also uses an upsidedowm balljoint but the weight of the car leans on the McPherson strut, not on the LCA, that makes a difference from the Alfa where the weigth of the car would hang on the balljoint.

I'm planning to go to a shop soon that sells parts for American cars, those cars use the correct type balljoint apparently so i'm off to look at some different ones. But if you find a good alternative i'm very interested.

[la_strega_nera]

Mercedes 190e uses an upside downtown ball joint I think. While it's a mac strut car, the spring is on the wishbone instead of the strut.

[MD]

Peter,
That ball joint type is correct. As for the size, obviously that could be another issue. If you give me a chance, I will look through my spare parts stuff and see if I still have the packaging for a generic brand and its part number. Otherwise, it will take a little longer but I will track one down from the parts suppliers and post the details for you.

..to be continued

[Giuliettaevo2]

Mercedes 190e uses an upside downtown ball joint I think. While it's a mac strut car, the spring is on the wishbone instead of the strut.

Mercedes is indeed a frequent user of the press-in type balljoint. But from what i've seen te balljoint has no threaded part to put a nut on. instead it uses a bolt through the spindle to secure the balljoint. So that's no good unfortunately.

[Giuliettaevo2]

The balljoint needs to be presse-in style, pressed in from beneath, so the protruding edge to stop it falling out needs to be on the opposite side of the threaded rod. Needs to have a threaded rod obviously. Must come from a car with similar suspension arangement, not from a McPherson equipped car for instance. And prefferably it has an outside diameter equal to the original balljoint or a little bit bigger.

Quite a list of demands i'm afraid...

[MD]

OK Guys, here's some info but you will have to do some digging yourselves regarding the dimensions. I suggest you contact the vending company and ask them for the dimensions of this ball joint (specifications) quoting the part number I have supplied in the photo.

Website : http://www.roadsafe.com.au/products.html

[PietereQ]

Hey Remco and others interested,
I just talked to a buddy of mine who is a huge classic opel freak, and he confirmed that holden gemini, and kadett c share the same platform suspension etc. I also had a look personally at the lower joint - the pressed part is plenty enough, after all that's what MD has. Also I don't really see how to mate it with LCA without any sort of sleeve, but that's no problem, really. What I'm interested Mike how have you modified the spindles to accept different joint? Any pictures from the build would be awesome
Thanks for sharing this with us man.

Ok off to ordering the joints

[Giuliettaevo2]

Hey Pete,

i just emailed that Aussie firm to confirm it but they couldn't say if the kadett was the european equivalent...

They had the balljoints in stock and were willing to ship them. I mailed them back asking for the dimensions but haven't got an aswer just yet.

Will let you know what they say.

The Opel joint is some 2 mm smaller. I happen to have a friend who owns a few, including one with 2.0 16v turbo engine from Opel Calibra.

[MD]

Peter,
If you go to page 3 of this topic set, you will see photos of how it is done. With the correct ball joint, the arm is remachined and the ball joint pressed in. It's not rocket science.

The thing is getting the hole size dimensions correct as making the fit too tight may cause the ball joint some damage or cause it to be too tight in steering.

The key thing here to remember is that this is only suitable for race cars because of the limited suspension travel they have. .

For a road car, there would be wheel fouling with full suspension travel -so don't even think about it !!