Monoball to replace ball joint in front a-arm
 

I have been told by several different people to replace the ball joints in the a-arms with monoballs for dedicated racecars. I was wondering if anyone could tell me the advantage to doing so as it appears that the stock ball joint can’t deform under load and the height of the stock ball joint is not that much different from the monoball when installed. Thanks

I've never heard or seen anything that replaces the ball joint with a monoball. Doesn't mean it doesn't exist though.

For the front, the only monoball I know of replaces the upper strut mount fitting with a monoball fitting.

Ahhh.....hmmmm...couldn't the lower ball joint be considered a "monoball" joint in the first place ???

I think the original poster might be referring to the upper shock mount, originally in rubber..to be replaced by a monoball. That would make more sense.

---Wil Ferch

No, I am aware of the monoball setup for the top of the struts. I already have camber plates that include these. I am referring to the modification to the A-arm to use a monoball instead of the ball joint. For instance, the ERP front A-arms come with this option.

Thats what I thought. How is the ball joint in the a-arm different from a monoball?

I agree. The ball joint is already a monoball. Same with the Turbo Tie Rod ends.

See the add in Excellence this month. First time I had seen it. Definitely a beefier piece than the factory ball joint. Actually it might have been the Kanna racing (sp?) web site where I saw it?? I will look around and post it when I find it.

VCI replaced my lower joint with a Heim Joint. This allows additional camber adjustment.

This is correct- Kevin from Kanna posted the following to the Rennlist a few days ago:

Althought the web page is still under construction, I have some of our products up. Check it out at www.KannaMotorsports.com
Now available are the KMS-Ohlins double adjustable strut for 911's with user adjustable spindle height. I also have a pic of the KMS Monoball Balljoint. This is a must for any 911 racer using stock front control arm suspension. They are a direct replacemnt for stock 911 balljoints. $150 a set till the end of the year....

Also, our rear Monoball cartridges are $190 a set till the end of
2003 I have several more products in the works, and promise to keep the cost in check.

I am irritated at the way some companies over inflate their prices
just because they can.

Kevin Schilling
www.KannaMotorsports.com

dad911, I have talked to the people at VCI about this. I am curious, how do you attach the strut to the heim-joint? Do you have a stud welded onto the strut that runs down into the heim joint?

Thank you all. You have been very helpful

Any been there done that opinions?
how does this piece feel/work in the real world?

brant

OK...I'll bite....maybe I'm dense...

If the "normal" ball-joint is a monoball...is this version simply larger with a bigger load carrying capacity...less distortion potential ? What's the theoretical rationalle behind all this?..

Wil Ferch ( feeling stupid... but honest with the question)

Dear Abbey,

I guess I'm feeling stupid too. The factory ball joint is a spherical bearing too, with no deflection, and is not known to fail frequently. I don't understand the benefit to this alternative part.

Plus the factory part has a weather seal and costs half as much.

Signed - confused in San Jose

From the website the balljoint-monoball looks much like the factory-balljoint, except:
- Maybe slightly larger diameter - can't be a huge difference though, they both have to fit into the same hole on the a-arm.
- No rubber seal - doesn't this location get pretty dirty in street use? (tho' I wonder why the rear monballs don't have rubber seals either.)
- Removable pin = another way to disconnect the strut from the A-arm - that could be handy, or another failure point to worry about.

Altogether...in my simple mind....a "net-sum-zero" kind of change, huh?

---Wil Ferch

Here is the answer provided to me from Kevin Schilling of Kanna Motorsports
“The Monoballjoint allows better front end control due to little if any
"give" in the ball, unlike the stock balljoint which rides on a plastic
insert.
We ran the stock balljoint and or Monoballjoint at Ohlins testing shake rig,
and the stocker deflected as much as .78 of a degree under load. The
Monoballjoint was a mere .016 degree!
Check out any Formula car....they all use monoballs.”