Does anyone have a cad drawing for mk2/mk3 ball-joint extenders I can have my buddy build me some, just need some dimensions.
This may be a really dumb idea.......but:
Why don't people use a solid piece of metal and relocate the ball joint mount to the top of the control arm? Seems like it would be a lot simpler and stronger ($15 worth of flat metal vs the $200 extenders)
Here is a very crude drawing showing what I'm thinking about:
Yellow blocks would be steel or aluminum and sandwich the balljoint mount. Get some longer bolts, and you can reuse the existing holes in the control arm. Thoughts?
What would be accomplished by extending the lower control arm length, all else equal? If the lower control arm is parallel with the ground nothing else changes...Camber curve remains the same...instant centers remain the same...other elements do change, what is being corrected?
Here's the thread. The part is manufactured from Ingalls Engineering, so I'm not sure why a CAD file is needed.
Although, it seems that extending the ball joint further out would also reduce its range of movement. That's one of the reasons that I never really followed up on them. I prefer to try and set the suspension up in a way that makes them unnecessary. OP: Are you interested in making them to use in a motorsport application?
Last edited by Light on Fuel; 10-04-2012 at 09:30 PM.
I was thinking about this modification this morning for a bit...I did play around with my drawing for a few minutes and without knowing the actual existing geometry and the change it's hard to see exactly how much camber gain/travel there is. But there may be some serious scrubbing forces at work here too as the suspension moves up and down...and I wonder what the influence is on roll center migration...I'll jump into this more later. Interesting though...not sure I've ever seen a ball joint extension...I've seen plenty altered to correct roll center height but that's in a vertical plane.
You need to lower where the balljoint connects to the spindle/steering knuckle. On MkII & III Golf and Jettas, you can use a ball joint spacer. Someone in Colorado makes them; a search of this forum will find them.
For the MkIV Golf and Jetta, the angle of the balljoint precludes using extenders, so you need to get spindles with lower attachment points for the balljoints, such as the Audi TT spindles or drop spindles produced by some Canadian company (again I forget the name, but search reveals all).
I was thinking about how in a daze my response above was...I still don't know what the OP is correcting or trying to change. But, moving the upper ball in or out relative to the car's centerline on an SLA design alters camber. Of course, altering camber also alters SAI.
Extending the lower ball joint on a MacStrut will increase negative camber, but it also places the strut mount in an odd position...assuming there is a stock strut mount in place. If there is a spherical bearing then all is well.
I'm on vacation and a bit buzzed so I'll not add anymore for now
If the lower control arm is perfectly horizontal then static lower control arm geometry has not changed. If the lower control arm is at some angle, then adding to its length changes its angle...perhaps immeasurable within the context of actual driving...but it does change within the pure context of geometry.
What this actual does depends upon the length of the control arm, the SAI angle, distance between the upper strut and lower ball joint.
I imagine, as I wrote above, that altering the lower control arm as a way of altering static camber might place some unwanted thrust load on a stock strut bearing...perhaps this is meaningless as well.
How does this part alter caster? I don't see, in side view, how the caster angle can be changed unless the ball joint pick-up point is offset. This isn't apparent in the photo.
I'm not knocking this modification, just pointing out a few things I see...might be a lot more that I don't see.
its because my car it low. I didn't plan on extending them outward, that WOULD cause dumb camber. I wanted to extend it upward like the PMW balljoint extenders so it would drop my control arm to get it parallel along with flipping my tie rods to reduce bump steer.
Except, as stated above - the angle of the physical control arm is not what matters, it is the angle that a line drawn between the LCA to chassis bushing center line and the ball joint pivot center line makes that matters. This happens to be about the same as just looking at the control arm, so people talk about level control arms, but if you just put the ball joint higher up on the control arm, and leave it in the same location relative to the bearing carrier, then you did not change anything about how the suspension works (but you probably created a future failure point).