Trying to understand ball joints

[38racing]

Not worried about low friction at this point. Just trying to understand how different length ball joints effect things. This will be for a metric stub chassis. Please correct me if I'm wrong: Longer ball joints on lca, drop chassis closer to ground and help to correct lca angle. I'm assuming you want these as straight (level) as possible. I assume this would also lower roll center? Longer ball joints in uca, give more angle for better clearance and help move the roll center to left or right depending on which side you lengthen? Sorry for the rookie question, I just don't know. Thanks for the help.

[Confused?]

Longer ball joints raise the roll center. Changing angle in the uppers also affects camber gain/loss. More angle, more gain. Less angle, less gain.

[Anonymous24]

Long stud upper ball joints set shallow inside the spindle can be used to create a taller spindle hypothetically. Taller spindles can reduce the amount of camber change in dynamic. Obtaining a 0° camber change I feel is optimal on the RF.

[Confused?]

0 camber change? I hope you mean caster change.

[Anonymous24]

No sir I do mean zero degree camber changeZero degree caster change is also preferable.

[Confused?]

Please explain your theory behind that. I can't get my head around zero camber gain. Are you talking about the wheel staying at, say 4degrees, throughout the motion of travel?

[dereksehi]

I think what anonymous means is after the car dives and rolls onto the rf from that point on you want zero camber change. From the studying I have done if you check it in the shop statically you want to gain between 1.5 and 2.0 on the rf depending on track banking and the tire you are running.

[Confused?]

That would make sense. But that does not equate to zero camber gain. That would mean he is trying to maintain the staic setting through the chassis movement. I get that.

What you are saying is, in effect, camber gain. What I perceive as zero gain would mean the tire stands up as the chassis dives and rolls over.

Thank you for tclearing that up for me. I was, as my name implies, confused.... LOL

[Anonymous24]

Camber change on the RF causes instability. I know that zero gain is impossible but keeping at little as possible is what we are trying to achieve

[dereksehi]

So if you have no camber gain on the rf when the chassis dives and rolls you want the camber to go positive? If you have no gain at the rf statically when checking it in the shop when the car dives and rolls dynamically you are going to loose rf camber because when the chassis rolls over the upper control mount moves out and the lower moves in therefore you will lose negative cmaber which to me wont plant the rf tire.

[stock car driver]

he obviously has no idea what hes talking about thus the reason he needs to be anonymous!

[Confused?]

Anonymous24, message me with the chassis company that you own/work for. Of all the chassis I've been around, none try to achieve zero camber gain.

[TCmod]

Depends on how you are measuring camber gain. If your doing it by raising and lowering the control arms or if you simulating chassis movement from static to hiked up at race height. Obviously you'll get major numbers just moving the spindle with car on stands. But bottom your rf out and jack your lr up or however you want to simulate race height then look at your numbers.

[Anonymous24]

When the car rolls in the corner you want the entire tire tread surface to be evenly on the track surface. That is most important part of the track. on the straight its important for complete tire tread but not as important. You never enter the corners at the same rate of speed hence you do not achieve the same amount of chassis roll at every corner. Say the chassis rolls 1° in turn one and you get 3° of chassis roll in turn three. Camber curve will kill you in this scenario because you cannotset the car two different ways for two different corners of one single track. Therefore 0° camber change during chassis roll would be optimum. In static you should set the camber to a degree that would be optimum for cornering. Am I making any sense yet.For those talking nonsense about me go get educated and then come back and let's discuss.

[stock car driver]

When the car rolls in the corner you want the entire tire tread surface to be evenly on the track surface. That is most important part of the track. on the straight its important for complete tire tread but not as important. You never enter the corners at the same rate of speed hence you do not achieve the same amount of chassis roll at every corner. Say the chassis rolls 1° in turn one and you get 3° of chassis roll in turn three. Camber curve will kill you in this scenario because you cannotset the car two different ways for two different corners of one single track. Therefore 0° camber change during chassis roll would be optimum. In static you should set the camber to a degree that would be optimum for cornering. Am I making any sense yet.For those talking nonsense about me go get educated and then come back and let's discuss.

So when I am banging on chip and my mph tops out at 87 or whatever it is for that gear EVERY lap you don't think Im entering the corner at the same speed lap after lap corner after corner?

[Anonymous24]

No. Take the corner up top you get x amount of roll. Enter the corner low and you probably will have increased chassis roll compared to the top. Especially if the track is progressively banked. Just cause you on the chip don't mean a thingto speed. You can be on the chip on exit because you broke traction. I pled my case. If I am incorrect please prove me so with actual data orprovide a credible source proving me wrong.

[stock car driver]

lol.. on the chassis dyno on the chip mph stays the same until you let off the gas. same speed at entry every lap. chip on entry not exit, lol.

[stock car driver]

You never enter the corners at the same rate of speed hence you do not achieve the same amount of chassis roll at every corner.

NEVER lol...

[powerslide]

Anonymous24, message me with the chassis company that you own/work for. Of all the chassis I've been around, none try to achieve zero camber gain.

Did that PM ever come?

[MM90]

I know the Bandit chassis that Mark Bush(sp) sets up that utilized the Ford stub tried for little if any camber change. Don't know how well it worked out for them or not.

[dirtrace09]

If you use basic geometry principles and draw sweep arcs, you will see that your upper and lower do not move at the exact same arc angle. This is due to many factors, including but not limited to, upper a arm angle and lower arm angle. Also length of each will come into play. Amount of movement will be a factor in camber gain. And theoretically you can control the camber gain, but real world racing will come into play. You can be at the same speed every lap if you are on a chip until you get into traffic and get held up for a split second. Will that be enough to drastically change your camber gain, probably not. Will the tracks progressive banking effect the movement, yes. However, you only have a limited movement the upper and lower a arms can make. You can simulate that and measure the gain and know the limit of that gain depending on your car.

[Confused?]

Powerslide, yes, it did. I won't post what he told me. If he wants to do that, that's up to him. However, he has very, very sound reasons behind what he posts.

[Anonymous24]

Thank you Confused? I appreciate you keeping my information private. I have reasons why I don't share my personal information on here. Too much drama. Thanks for being an awesome guy! I will not forget that!!