Metric front end help

[Steve_Voisinet]

Why would you be concerned with what the RF does during droop? I would be more concerned with camber gain in the RF during compression.

He said he is working on the drivers side = LF

[dexleo2]

How much droop are you messing with? And where are you measuring it? if your car is together just jack the frame up and lift the lf a few inches and then see what you have at a reasonable amount of droop.

Stock car Driver,

I'm just messing around with how the front suspension works and how it relates to the car, I don't have it all together yet. What I have been doing is raising the spindle up to where I have about 4 degree angle going up to the upper ball joint, and assuming this will be around the ride height and that is where I took the measurements with my caster/camber gauge. Then I let the suspension all the way down (bottomed out) and then took the readings again and compared them. Its not the most scientific way of doing this, and I don't think the suspension will ever drop that far on the Drivers side during a race, but I'm just trying to understand what the front end is doing when its rebounding or compressing. I'm not really sure what I will have for drop on the drivers side yet its a medium bank track I plan to run at. What would be the typical drop or any idea's on how far the suspension will move. Thanks again...

[moving violation]

Josh just sent you a PM

[dexleo2]

a good ride height would be lower level, center of inner bolt to center of lower bj
droop if you measured from top of frame to the tube a arm 1.5 would be plenty

Thats what I will set it up for then... Thank you again Stock Car Driver

[fast_crew]

sorry I was working of the Left front...

My bad thought I seen RF there somewhere. Brain fart, atleast I can admit when I have one of them... When measuring camber at ride height with an up hill angle in UCA you should gain + camber untill UCA is level, then you start to lose camber with continiued droop. How much droop do you have before you start losing camber? If this droop seems adequate you could set the shock up to limit the droop, maybe add an extra inch for insurance if it seems needed.

[fast_crew]

Dude, your wrong. U need to re read and THINK about the shim and upper bj angle on the RF... or re read what Ive already told you previously, its really very simple.

So your saying put this shim under the RF b/j, between the UCA and the b/j and you gain compression before binding??? Again it doesn't matter how many times you flip this shim it's still thicker on the outer edge, and will put the RF b/j at more angle and cause binding earlier.... I suppose you could mount the balljoint on the bottom of the UCA with the shim between them and this wouuld work, may require some grinding on UCA and shim. You will figure it out eventually Jeff.

[fast_crew]

Man I hope nobodys listening to you who is new to this sport, shocks cost way too much money to use like that and ruin them.

What part of "if this droop seems adequate" do you not understand, "what part of add an extra inch if it seems needed". get over yourself. While I don't like the shocks topping out, do you think we should put chains on the front axle of the sprint car so we don't damage the $$$ gas charged Bilstein shocks we run???

[dexleo2]

My bad thought I seen RF there somewhere. Brain fart, atleast I can admit when I have one of them... When measuring camber at ride height with an up hill angle in UCA you should gain + camber untill UCA is level, then you start to lose camber with continiued droop. How much droop do you have before you start losing camber? If this droop seems adequate you could set the shock up to limit the droop, maybe add an extra inch for insurance if it seems needed.

That makes sense... That has to be what I have been seeing with my caster camber gauge... Since I have been just setting it up for a general ride height and then letting the suspension drop to where its bottomed out and then taking another reading at the bottom of the travel. I missed the level and just caught the bottom and the ball park ride height. Makes perfect sense.... Thank you Josh K.

[fast_crew]

Wow you finally got it, congrats! I figured you would get it eventually, it really isnt that hard. There would be no grinding needed on the a arms people in this thread are talking about.

Wow what a life saver I was to give you this idea... where did you ever say to mount under the UCA. You simply stated flip the shim...

[fast_crew]

I said lots of things to try and get you to understand how it works all for not obviously since you dont work on street stocks you work on something like a monster truck that needs 9-14 of stagger to turn, lol.. Is your other user name Ego?

If I did need it I would be mounting it underneath on BOTH sides for it to work in its intended method which is to put the bj more parallel to the ground, thats completely obvious to everyone but you for whatever reason.

Yeah you didn't... leave it at that.

[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]

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]

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.