Camber Gain

[autoxcuda]

Another thing to be aware of when using extended upper ball joints particularly where using them with FMJ spindles the angle of the ball joint stud to ball joint body increases as things get taller... Under full compression that angle increases further... You can reach the maximum angle & when that happens something has to give.... On Fords that happens at about 1.25" & then the stud on the ball joint fails.... Don't know where that point is on a Mopar.... On Fords the fix is an angle plate between the ball joint & control arm....Mopar ball joints screw into the arm, there's no angle plate option....

These special circle track derived ball joints run at higher angles.

We’ve run them on race cars at way higher static angles than you can get with a stock mopar. And then have 3-4” of travel additional.

 

[72bluNblu]

Another thing to be aware of when using extended upper ball joints particularly where using them with FMJ spindles the angle of the ball joint stud to ball joint body increases as things get taller... Under full compression that angle increases further... You can reach the maximum angle & when that happens something has to give.... On Fords that happens at about 1.25" & then the stud on the ball joint fails.... Don't know where that point is on a Mopar.... On Fords the fix is an angle plate between the ball joint & control arm....Mopar ball joints screw into the arm, there's no angle plate option....

These special circle track derived ball joints run at higher angles.

We’ve run them on race cars at way higher static angles than you can get with a stock mopar. And then have 3-4” of travel additional.

And the FMJ spindles are only ~3/8” taller than A body spindles.

 

[racerjoe]

Careful those slow *** Miatas run some pretty good lap times.
View attachment 1715838268
Me picking up the inside rear at COTA

I was in the first gen Miata, which handles great, but dammit they are slow. My local track has a 1/2 mile straight and it topped out at 90mph (completely stock car). It was fun going through the esses at 75mph though.

 

[racerjoe]

You don't specify and I can't tell in the first picture if the car if the car is 'pushy' when you are on the brake, rolling or under part throttle?
If it's under braking you're driving in too deep and need to be off the brake at or before the apex.

A rear bar will tighten the car up, not remove the push.

Try lowering the front tire pressures (if it's pushing from the middle off) and/or loosen up the front swaybar. That's the easiest thing to try first.
If you're real serious, loosen up the T bars (springs) and limit your travel using adjustable bump stops. Then tune with shocks and tire pressures.

If it still won't co-opperate from the center (apex) off you'll have to loosen the car up with the gas pedal.

One thing though- I have never done slow speed autocross parking lot racing so take it for what it's worth.... but I did stay at a Holiday Inn one night
View attachment 1715838343

Parking lot racing... I love it!

Thanks for the input!

 

[racerjoe]

Uhh, do those UCA's look like this?

View attachment 1715838381

Because if they do, they were made by CAP. And that means they can end up looking like this...
View attachment 1715838382

CAP was bought out by QA1. Some of their designs were good (like their tubular LCA's, which are basically the same as QA1 LCA's). But their welding and quality control was dangerously bad. I cracked a weld on my CAP tubular LCA's on my Challenger. No catastrophic failure like the UCA's usually had, but bad regardless.

If you have CAP uca's, you want new UCA's anyway. The second gen SPC's are cool, but for an A-body I'd run the 1st gen ones. I have them on my Duster. Not as spendy and just as adjustable.

As for the camber gain, Steve and TT5.9mag have absolutely nailed it. The only thing I would add is that I wouldn't mess with the ball joint spindle lengths unless I had totally plotted out the suspension geometry on YOUR car. Because how your car is set up will change what you want. Sure, you can get close by looking at a general A-body suspension plot, but changing the upper ball joint height is really a fine tuning thing, so, you'd want it specific to your ride height, the rest of your suspension components etc. I wouldn't change the ball joint spindle height on my car based on Steve's plot, for example.

Well that looks like the UCAs I have. I didn't know they were prone to breaking. I'll make sure to inspect mine. I feel like if there was a weld penetration problem on them, they would have broken by now. I do like the first gen SPCs, and I'm sure my alignment guy will like the too.

 

[72bluNblu]

Well that looks like the UCAs I have. I didn't know they were prone to breaking. I'll make sure to inspect mine. I feel like if there was a weld penetration problem on them, they would have broken by now. I do like the first gen SPCs, and I'm sure my alignment guy will like the too.

You're probably right, I won't go as far as to say every UCA that they built was garbage. It was a quality control issue, some had very cold welds and some of those broke. I ran both the UCA's and the LCA's on my Challenger for years and tens of thousands of miles without any issues. Eventually a weld cracked on one of the LCA's, but I never had an issue with the UCA's like others did. Still, I pulled the UCA's when I replaced the LCA's. The CAP products that had welds were a crap shoot.

I love the 1st gen SPC's, they make doing alignments so much easier. Your alignment guy will love them.

 

[BergmanAutoCraft]

I have the FMJ spindles already.

SPC makes 2 generations of upper control arms. I carry them both. I'm also the only one who makes proper sleeves and spacers to fit the delrin bushed ends into our mopars. The first gen arm uses a stock K772 upper ball joint. Although it comes with stock height UBJs, it can be retrofitted with any of the Howe extended length joints. The second gen arm uses an SPC proprietary joint that is a 1/4" taller than stock. Longer joints and delrins optional here too.
The use of the FMJ spindle is an improvement in feel as it reduces body roll to a degree. The 3/8" taller spindle shortens the moment arm between the center of gravity and the roll center.
Its hard to tell from the photo exactly what the car is doing. The speed must be fairly low and the rear tire sidewall doesn't appear to be distorting. Your comment about adding a rear bar is a good idea as a tuning aid. Since auto cross can have some weird tight turns due to course design, some things may have to worked around. Having experienced may open track days, I'd say some of the setup may be a little different among the two.

 

[autoxcuda]

SPC makes 2 generations of upper control arms. I carry them both. I'm also the only one who makes proper sleeves and spacers to fit the delrin bushed ends into our mopars. The first gen arm uses a stock K772 upper ball joint. Although it comes with stock height UBJs, it can be retrofitted with any of the Howe extended length joints. The second gen arm uses an SPC proprietary joint that is a 1/4" taller than stock. Longer joints and delrins optional here too.
The use of the FMJ spindle is an improvement in feel as it reduces body roll to a degree. The 3/8" taller spindle shortens the moment arm between the center of gravity and the roll center.
Its hard to tell from the photo exactly what the car is doing. The speed must be fairly low and the rear tire sidewall doesn't appear to be distorting. Your comment about adding a rear bar is a good idea as a tuning aid. Since auto cross can have some weird tight turns due to course design, some things may have to worked around. Having experienced may open track days, I'd say some of the setup may be a little different among the two.

Does the second gen UCA accept common replacement traditional K772 ball joints? Which also fit modular UBJ like Howe offer?

 

[BergmanAutoCraft]

Does the second gen UCA accept common replacement traditional K772 ball joints? Which also fit modular UBJ like Howe offer?

It doesn’t. I wrote proprietary ball joints in the description.