Metric front end help

[speedbuggy]

Well, I think you're both right about what affect that shim will have on the ball joint angle. I should have looked at it closer.

I don't want to mount the ball joint under the UCA, so I may have to make my own after all.

There's $40 down the drain...

[fast_crew]

I tack weld my upper bj to the arms.

A lot of guys around here run the bj under the arm, they think it changes the angle of the upper arm for the better, lol..

When we ran PS and had to slot the LF UCA to slid the b/j out, we always tacked ours aswell.

A few guys where mounting theres under the UCA out this way, I laughed at that aswell. They couldn't comprehend that the b/j pivot was still in the same place. Ive never tried to mount them under the UCA.

[dirtman45]

I laughed at that aswell. They couldn't comprehend that the b/j pivot was still in the same place. Ive never tried to mount them under the UCA.

It's to do with the angle of the arm. Draw it on a piece of paper if you don't understand it. On the LF more upward angle to the outside allows some camber gain the correct way, as it drops down.

[Steve_Voisinet]

Dirtman,

When you draw the line you are referring to - the line goes through the a-arm inner pivot points and the upper ball joint PIVOT POINT. It make no difference if the control arm is above or below the ball joint, the line you draw will still be in the same place.

[billy5]

underneath

you could put a 1 inch spacer between the balljoint and the upper control arm and you still have the pivot points in the same place.....it just adds alot of angle to the a-arm but does nothing but makes it bind sooner......you need to raise the pivot point up.

[dirtman45]

Dirtman,

When you draw the line you are referring to - the line goes through the a-arm inner pivot points and the upper ball joint PIVOT POINT. It make no difference if the control arm is above or below the ball joint, the line you draw will still be in the same place.

I know the pivot point is in the same place, I'm not arguing that. If you have a flat upper arm that sits flat with the ball joint on top, then the arm will sit angled upward with the ball joint on the bottom of the arm. Is everyone following along here?

When that corner drops (LF) the one with the flat arm will start to pull the top of the tire inward as the arm begins to now aim downward. The one with the arm already angled upward will try to flatten out as the tire drops. As it flattens out it pushes the top of the tire outward. Can't you understand this?

[billy5]

binds

but in the other range of motion it creates a sooner bind..and thats worse ..

[dirtman45]

That's why you use the tapered spacer to get the ball joint angle back where it should be.

I know,.... way to much put into this thread already. I'll leave it go away.

[fast_crew]

I know the pivot point is in the same place, I'm not arguing that. If you have a flat upper arm that sits flat with the ball joint on top, then the arm will sit angled upward with the ball joint on the bottom of the arm. Is everyone following along here?

When that corner drops (LF) the one with the flat arm will start to pull the top of the tire inward as the arm begins to now aim downward. The one with the arm already angled upward will try to flatten out as the tire drops. As it flattens out it pushes the top of the tire outward. Can't you understand this?

Your theory or logic is correct, but you need to reference your camber changes to the pivot points not the angle of the arm holding the b/j, look at a stock UCA for instance. Example, You could put 4" of spacer in there, and it won't change the camber gain even alittle. You could make and UCA shaped like a upside down "U" using 2' of tubing and it would still have the same camber change. To gain anything a pivot point has to be moved, which means taller spindle, longer b/j's, or moving the C/A mounts.

[speedbuggy]

Your theory or logic is correct, but you need to reference your camber changes to the pivot points not the angle of the arm holding the b/j, look at a stock UCA for instance. Example, You could put 4" of spacer in there, and it won't change the camber gain even alittle. You could make and UCA shaped like a upside down "U" using 2' of tubing and it would still have the same camber change. To gain anything a pivot point has to be moved, which means taller spindle, longer b/j's, or moving the C/A mounts.

What he said...

I actually had begun typing up a paragraph about tire contact patch and spindle movement, but then decided....naahhhh.....I'm not dragging this thread out another three pages worth.

[TeamTerminator]

Upper ball joint under a arm

I mount the ball joint under the control arm for the simple fact of changing a bent control arm with out having to beat on the spindle to get the ball joint out. As long as the ball joint isnt bent which usually werent in my cases cuz of the junk IMCA upper a arm is junk this works out pretty good. Ball joint plate on the control arm isnt thick enough for the abuse we put them under.

[C10]

All components and mounts must be steel, unaltered OEM, in OEM location and match frame. OEM rubber A-frame bushings only. OEM or OEM replacement ball joints allowed. No rebuildable ball joints. No sway bars, spring spacers, chains or cables. Exceptions are: for 1978-1987 GM mid-sized metric frame, OEM upper A-frame may be replaced using aftermarket upper A-frame (steel or aluminum cross shaft allowed), must display “IMCA approved” decal on top of rear tube of A-frame; bolt on spindle savers allowed. Upper A-frame mount must remain OEM and cannot be moved.


Right from my Officials IMCA rule book. Just sayin

[stockcar5]

All components and mounts must be steel, unaltered OEM, in OEM location and match frame. OEM rubber A-frame bushings only. OEM or OEM replacement ball joints allowed. No rebuildable ball joints. No sway bars, spring spacers, chains or cables. Exceptions are: for 1978-1987 GM mid-sized metric frame, OEM upper A-frame may be replaced using aftermarket upper A-frame (steel or aluminum cross shaft allowed), must display “IMCA approved” decal on top of rear tube of A-frame; bolt on spindle savers allowed. Upper A-frame mount must remain OEM and cannot be moved.


Right from my Officials IMCA rule book. Just sayin

those are hobby stock rules not stockcar.
either way, i'm sure imca would have no problem with a racer reinforcing a weak spec part to make it last longer and save some money right? after all they are "the home of affordable racing"

[C10]

That is correct, but the OP is inquiring on a hobby stock.

[streetstockguru]

shims

Would the shims from Metalwerx still be needed if running aftermarket UCA with camaro spindles on stock metric LCA?