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anyone make roll center correction ball joints for the 99-03 cars?

CadVetteStang

CadVetteStang

New member
I have looked and can't find them anywhere. I would settle for an adaptor to mount a 4 bolt ball joint since you can find those longer than stock length to put the A-Arm back to a good angle when lowering the front suspension.

BTW, new here. First post. Been looking at some of the threads here. Looks like a good stock of suspension gurus hang out here.
Thanks in advance,
Cody
 


Cody.. the only guy I know of that took this on was 95NASTA, he's on a few different 3800 based forums and if you google, likely you'll find Mike doing something interesting.
 
your only real option is to use an old bj mount (ball joint cutoff) as a spacer and bolt the ball joint to the top of the arm

i believe his fix involved the chrysler joint and modified arms/knuckles but maybe im thinking of ron vogel
 
Okay; thanks. That at least gets me headed in the right direction. I am afraid that if I lower the car, the lower A-Arm will tilt up towards the wheel instead of level or down. In that case, the trade off would be that while a lower center of gravity is good, a lower roll center is VERY bad for cornering. I would rather race autocross with a stock ride height in a car that actually turns than lower it and look cool while understeering flat and mowing down cones.

Anyone ever check the level of the lower arm after lowering? How low makes it level? How low causes it to tilt up?
If the arm is tilted down, the car also gains SOME negative camber as the tire loads going into the turn. If the a-arm is tilted up with a Macpherson strut suspension, the wheel actually tilts outward with positive camber that coupled with a roll center that is actually below ground, means that a stock car on soft struts and springs actually handles better on a solo course.
 


the way we correct this now is to space the motor/trans up a little bit. it's the easiest way to attack it without doing a lot of work, really.

that is, if you can afford the lost hood clearance.
 
This is why im not slammed either. My coilovers are mounted high enough that I can lower the car without affecting geometry. If I get off my ass one day and just have the strut rod cut down I can get another inch or two just by doing that.
 
I can see where spacing the engine and tranny up some will correct the drive axle angle, but that would not effect the angle of the a-arm. Can the K-Frame mounts be safely deleted to raise it up? That would raise the inboard a-arm attachment point instead of lowering the outboard side.
Also, on the outboard end, I can see the camber advantage for using a ball joint spacer to drop that side of the arm, but that would not lower the pivot point of the ball joint, so I am not sure how effectively that would change the roll center.

If…. And this is VERY big if….. If, I could get a manufacturer to build a long stem 3 bolt ball joint (reinforced to account for the extra stresses) would there be a good market for it? Do enough w-body owners understand what negative effects a lowered car without a raised roll center has? If I could get a factory to build them, they would want a minimum order to tool up for it or the price would be outrageous.

A long stem ball joint with ¾” inch on a 16” wheel or 1 ½” on a 17 “ or 18” wheel should do the trick. The shorter one on the 16 inch wheel or it would rub the inside of the wheel.
 
CadVetteStang said:
would there be a good market for it? Do enough w-body owners understand what negative effects a lowered car without a raised roll center has?
Click to expand...

No, the group as a whole is too cheap, cars becoming too old and most don't drop that low that they experience issues they feel need to be corrected.
 


I spoke with QA1 on the phone; their racing ball joint is not for street use because it requires maintenance every few hundred miles; and with my 50 mile per day drive, I would be jacking my car up to service it every week.
That is why they do not offer a GM 3 bolt ball joint, because not many have fulltime racecars with our GM Macpherson strut setup….. But the good news is, they are pondering a line of streetable products for cars not fully dedicated to racing…. So, I asked them to look into our ball joint as a future development. I did not get a “no” … it was more of a “hmmm” ……..
So, I will look up 95 NASTA and see what he came up with using a Chrysler ball joint.
 
they wont

your best option is as i said, use two junk bj's as the baseplate (cutoff ball section), use 3 longer bolts, and bolt the ball joint to the top of the arm.

instant 1/2-5/8ths inch roll center correction for cheap and just as strong as factory., if your wanting double shear, then its just a plate welded to the lca after bolting together with the plate on top with the new ball joint.

with how long our threaded section is you could get tapered sleeves turned to move the knuckle up on the ball joint shaft, but thats weaker.

you could section another knuckle onto the bottom of yours, safety depends on yer welder, exact positioning difficult.

welding threaded chrysler sleeve to oem LCA and using chrysler joints. good luck getting the geometry close.

the suspension on these sucks, but any suspension can be made to work if cubic dollars are present.

youd be miles ahead spending the money on some damn good trans coolers if your wanting to get around a road-course fast...for more than one lap
 
thanks. I have also thought about sectioning another outer portion of a LCA end on top and using that one as the ball joint mount. I think it could be done as a bolt on without loosing strength, but I have not yet given it a close look for cut points and bolt holes. This is no place for guesswork, however. whatever I do, it must be strong and safe.
 
meh parkave subframe+C5 lower control arms and upper control arms weld a mounting bracket for a shock through the wheel well. weld the other bracets to the same structure
 


I have been thinking about this for a long time as I want to lower my car but I also autocross it. I haven't looked if it was possible but I want to cut off the factory mounting points for the LCA and weld in mounts for these control arms a couple inches higher on the subframe. The other option I've thought about and I haven't looked to closely if this is possible, is to have the bottom of the knuckle machined flat, drill and tap it at each corner for 4 bolts, and then have a block of metal machined to fit the ball joint that the ball joint can bolt to, and then the block can bolt to the bottom of the knuckle. Kind of like how a Volvo 240's ball joints are set up.
(Like this only thicker)
newballjointjune10a.jpg

Someone mentioned that you could space the ball joint up on the LCA. This will change the angle of the control arms but will not effectively change the roll center, as the relationship between pivot of the ball joint and the pivot of the LCA will not be changed.
 
I have been thinking about this for a long time as I want to lower my car but I also autocross it, and came up with two ideas. I could cut off the factory mounting points for the LCA and weld in mounts for these control arms a couple inches higher on the subframe. The other option I've thought about and I haven't looked to closely if this is possible, is to have the bottom of the knuckle machined flat, drill and tap it at each corner for 4 bolts, and then have a block of metal machined to fit the ball joint that the ball joint can bolt to, and then the block can bolt to the bottom of the knuckle. Kind of like how a Volvo 240's ball joints are set up. I'm not sure if our knuckles would accommodate that sort of thing.
(Like this only thicker)
View attachment 13378

Someone mentioned that you could space the ball joint up on the LCA. This will change the angle of the control arms but will not effectively change the roll center, as the relationship between pivot of the ball joint and the pivot of the LCA will not be changed.


If anyone comes up with a working solution, please keep this thread updated.
 
For Autocross, keep in mind that if you change the suspension mounting locations, your car is automatically placed in one of the modified classes as opposed to one of the street prepared or touring classes. If you don't care about being competitive, no problem, because you will be racing against cars with much better weight distribution, $20,000 worth of suspension, 14" brake rotors, and 500 horsepower.

If you put whatever suspension components you want in the stock mounting locations, you will race against some FWD daily drivers and some novices in really fast cars who are fun to beat because they don't know how to drive.
Personally, I don't care what class I am in so long as I can pick off some Mustangs and BMWs.

IMO, a W body car is most competitive in a stock class with sticky street tires and a skilled driver.

But, if modifications are to be made, then a lengthened spindle that drops the ball joint down far enough to correct the roll center (or a correction made by a longer ball joint) would be necessary for a lowered car. Neither of these things change the stock location of the suspension. However, one could argue that the long steering knuckle does make that change by moving the ball joint mount.

And I did more checking.... Outonthetiles is right. A ball joint spacer does not change the roll center. It is the pivot point, not the final angle of the LCA that determines that. A spacer is just a waste of time and effort.
 
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