Suspension Builders: Ball-Joint or Spherical?

[ckiesz]

Sorry to re-word a previous thread, but I am hoping to get a little better feel of what people are using.

I am concered with one point on the suspension, the lower outer pivot on the front suspension. (Double a-arm with coilover attached to lower).

Here's the question: What is the appropriate bearing or joint to use here?

I have seen 0.75" spherical bearings(not talking about threaded rod ends) used for this point, which seemed like a great idea, until I started seeing the load ratings in the bump/rebound direction. With load ratings in the 6000-7000lbs range, I would think the cars weight, in a corner, plus any aero, while hitting curbing, would want to press the ball out of the housing. Am I wrong in my assumptions?

Would an oem style ball joint be better?

Any insight would be much appriciated,
Christian

[Nero]

Work on 1/2 car weight, plus aero X 3G for circuit only car plus safety margin you think is reasonable = side load on bearing.
Of course road car components are far more capable, they are from a heavy road car designed to take pot holes etc...but they are heavy and not always easy to package.

[ckiesz]

Thanks for the response. When you say side loading, are you refering to the bearings strong or weak direction? Sorry for the newbie questions.

Is there a different type/style of spherical bearing that would be better than a high grade Aurora spherical in the bearings press-out direction?
Christian

[Nero]

yes, in essence trying to push the ball out of the side of the bearing.
Aurora are a fine mid-priced bearing Co. You choose the bearing dependant on use and budget - ideally you want a stainless (rust proof) 3-pc Teflon lined high misalignment spherical bearing. You can find plenty of catalogues online with the required data....if you are not in a rush keep checking USA ebay etc for ex-military surplus would be suggestion.
http://www.pegasusautoracing.com/pro...p?Product=3072

[Goran Malmberg]

I recomend some standard ball joint. On my own car I use Saab 99 balljoint.
They are cheap and bulletproof in all directions. Look at the whole arrangement at my site, klick "Rollbars springs shocks and A-arms".
As for the upper A-arm and chassis mount some type of spherical bearing is good. If you use heim joints, possition the tapped part in line with load, look at my rear upper A-arm. You may even throw an eye on the Corvette A-arms fare down the site. Sorry, but the lower ball joint is out of sight, but the inner ones is in good wiew.
Goran

[ckiesz]

Should I be watching for heat resistance and brake disc proximity?

Goran Malmberg: does the corvette also use the Saab joints?

[Goran Malmberg]

Originally Posted by ckiesz

Goran Malmberg: does the corvette also use the Saab joints?

No, I could check up what car is was made for. The Saab uses a Fork shape bolted mounting which is great for also attaching the coilover in to. The Corvette has pushrod mounted very fare out the A-arm not to get bending loads in to the thin wing profiled arm. So, the balljont is a round press fit in to a cylinder shaped end of the A-arm.
Goran

[Nero]

I do not think you need to worry about heat resistance, the bearing should no get that hot.
The road car ball joints Goran and I are mentioning are applicable for a heavier car and naturally can be used on any car, but a single seat formula style car can use a much lighter component.
You have also not said which end of the car this is for.

[ckiesz]

I am refering to the front suspension. The car should be between a le mans gt2 and gt1 car with no rules, and using it for unlimited time attack style road races. It should be 2200-2400 lbs, 500-600 hp, very large race tires, and playing with some serious aero ideas.

[Goran Malmberg]

Lets see if these pictures comes up Ok.
For such fast car wit lots of grip I recomend about the same balljoint arrangemant as on my Corvette build. The "round" style ball joint are light compared to strength as there are no "fork" mounting. On the other hand some coilover mounting must be welded in place. One big advantage of this round ball joint arrangement is, that if you look at the picture, the A-arm leg centreline is focused to the centre of the of the balljoint. Together with fare out pushrod mounting this lessen the load a lot on the A-arm itself for a lighter average construction.
http://rejsa.nu/im/_racing/446-new_2...julupp_004.jpg
http://rejsa.nu/im/_racing/446-new_2...aarmaarufl.jpg

Goran

[ckiesz]

No go on the pictures, just flashes "error". You can email them to me if that helps, as I am currious. ckiesz@aol.com

There are a handfull of "racing" ball joints available from stock car companies like howe racing, but like most stuff in those catologs, they are based on a 1970's chevy or something else big and heavy.
I'd be interested in what is available for more of a thoroughbred race car.
Thanks,
Christian

[Goran Malmberg]

I just mailed you the images.
Goran

[ckiesz]

Looks good. I like to idea of the bearing being retained by a cup that can be built into the arm. The loads look like they are happy to go in the right direction.
Christian

[Goran Malmberg]

If you are not in to much of a hurry, I will come up with the ball joint parts number for you.
Regards
Goran

[Dennis de Rooy]

Hi ckiesz and Goran,

Would you mind emailing me the pics aswell? I'm interested in this and I can place them on a webserver for every reader of this topic to see them.

dennis [at] dennisderooy.com

Thanks, Dennis

[ckiesz]

Goran- I have been away form the computer for a while, but I am still curious as to what you are using, if you time allows. Thanks much,
Christian