Camber and Ride Height....

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ACME SS

ACME SS

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So I have read a few threads on ride height and many of the members are saying to set it to what you like... In my case, the car was level along the rockers and looked pretty good so when I changed out my control arms I put it back that way.

I started another thread on here asking about an online alignment calculator but instead of hijacking my own thread, I thought I would start this one since a tool such as that would be helpful in determining which way to turn the two eccentrics since it blows my mind at times. My issue as I attempt to align the car (71 Demon with new QA-1 control arms and adjustable strut rod) is that the camber seems to be excessively negative to the point I can't get camber and caster to both be in spec. I just had a thought... the two eccentrics are the only adjustment on the upper control arm but the torsion bar tensioner (ride height ) would affect camber, would it not?? And if I am correct, the fix for lack of positive camber adjustment would be....to lower the front, i.e. detension the torsion bars?
 
You have added so many adjustment points into the system that you might be better off taking it to a professional shop — and not just a local tire shop, which will complain "it's not in the computer" and then try to match the exact specs in the FSM (which are horrible for modern tires). You should find the custom alignment shop in your area used by racers and get a performance alignment.
 
mvh said:
You have added so many adjustment points into the system that you might be better off taking it to a professional shop — and not just a local tire shop, which will complain "it's not in the computer" and then try to match the exact specs in the FSM (which are horrible for modern tires). You should find the custom alignment shop in your area used by racers and get a performance alignment.
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Absolutely false... Same eccentric bolts are used on upper control arm. The QA-1 strut rod is simply adjusted to length and has ZERO input in the alignment. The QA-1 control arms are designed to give additional camber...which is why I'm thinking I need to possibly adjust the ride height.
 
Lowering the car tends to increase negative camber. Raising it makes the camber more positive.

Negative camber is when the tires are tipped in toward the car. Think about it this way, the control arms move in a circle around their mounting points. Lowering the car rotates the control arms upward toward the car, which tips the tops of the tires further in.

There's a ton of info you need to cover here. What is the current ride height of the car? What alignment specs are you trying to achieve here? How did you go about setting the length of the adjustable strut rods?

ACME SS said:
Absolutely false... Same eccentric bolts are used on upper control arm. The QA-1 strut rod is simply adjusted to length and has ZERO input in the alignment. The QA-1 control arms are designed to give additional camber...which is why I'm thinking I need to possibly adjust the ride height.
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The QA1 control arms are designed to give extra caster, not camber.
 
72bluNblu said:
Lowering the car tends to increase negative camber. Raising it makes the camber more positive.

Negative camber is when the tires are tipped in toward the car. Think about it this way, the control arms move in a circle around their mounting points. Lowering the car rotates the control arms upward toward the car, which tips the tops of the tires further in.

There's a ton of info you need to cover here. What is the current ride height of the car? What alignment specs are you trying to achieve here? How did you go about setting the length of the adjustable strut rods?


The QA1 control arms are designed to give extra caster, not camber.
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Thanks, I understand alignment terms...just never aligned a torsion bar front suspension before and it just dawned on me that is probably why I can't get more positive camber. I had the raise vs lower backwards but that is the issue I'm dealing with. I will raise the front tomorrow and that should give me more positive camber and thus allow me to obtain both camber and caster simultaneously. I'm shooting for -.75 camber and 3 positive caster, 1/16 toe in. All parts are installed per QA-1 instructions...no issues there. Just didn't think about the height affecting the camber until now.

You are correct, they provide up to 3 degrees additional caster, my mistake.
Thanks
 
Are you using turn plates with your fastrax gauges?
 
Also keep in mind that your strut rod length will also effect your caster setting. If the strut rods are too long, they'll push the control arm back and reduce positive caster. Alternatively if they're too short they can increase positive caster.

But the strut rods aren't there to adjust caster, the length has to be set so there's no binding in the LCA through its entire range of travel. Setting them properly may in fact change your caster setting, but that's not what they're for.
 
72bluNblu said:
Also keep in mind that your strut rod length will also effect your caster setting. If the strut rods are too long, they'll push the control arm back and reduce positive caster. Alternatively if they're too short they can increase positive caster.

But the strut rods aren't there to adjust caster, the length has to be set so there's no binding in the LCA through its entire range of travel. Setting them properly may in fact change your caster setting, but that's not what they're for.
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Yep, they are adjusted perfectly with zero binding.
 
72bluNblu said:
Also keep in mind that your strut rod length will also effect your caster setting. If the strut rods are too long, they'll push the control arm back and reduce positive caster. Alternatively if they're too short they can increase positive caster.

But the strut rods aren't there to adjust caster, the length has to be set so there's no binding in the LCA through its entire range of travel. Setting them properly may in fact change your caster setting, but that's not what they're for.
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The factory lower control arm probably had 3-5 degrees of slop wore into them.
 
@72bluNblu , hey thanks for the advice. I increased the ride height this morning and it only took 6 moves on the first side to get my numbers I was shooting for. Now on to the other side. I appreciate members who help a guy think through a situation.

I had actually done a search on ride height prior to my alignment and found an older thread where pretty much everyone was saying to set it to what looks good. There were pictures of their cars stance and everyone was like "if it looks good its good". I had gone on that thread thinking the setting had an impact on alignment but ended up being led astray. I don't like the term "ride height", as it is way more than stance but it determines the ability to hit the camber settings.
 
ACME SS said:
@72bluNblu , hey thanks for the advice. I increased the ride height this morning and it only took 6 moves on the first side to get my numbers I was shooting for. Now on to the other side. I appreciate members who help a guy think through a situation.

I had actually done a search on ride height prior to my alignment and found an older thread where pretty much everyone was saying to set it to what looks good. There were pictures of their cars stance and everyone was like "if it looks good its good". I had gone on that thread thinking the setting had an impact on alignment but ended up being led astray. I don't like the term "ride height", as it is way more than stance but it determines the ability to hit the camber settings.
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Measuring the ball joint height, or balljoint vs pivot distance is the way the factory manual shows to do it. @72bluNblu has often posted that page, and also describes where he has his car adjusted as an example. It's worth reading. The "if it looks good, it is good" can be correct depending on your goals, but going by proper measurements seems far more repeatable to me.
 
It really just depends on what parts you’ve got and what you’re willing to do. You can lower the car a little bit with the stock parts and a little more if you have aftermarket UCA’s with more caster built in, but there are definitely limits and all of these cars are a little different- they were from the factory and 50 years later that’s only gotten worse.

On my Duster my A-B measurement is 0. But I run SPC adjustable UCA’s, adjustable struts, QA1 LCA’s, modified bump stops, 1.12” torsion bars, etc to make all of that work.

Geometry wise, it’s better to be lowered than at stock height if you’re running radials, but you do have to be able to set a decent static alignment still.
 
72bluNblu said:
It really just depends on what parts you’ve got and what you’re willing to do. You can lower the car a little bit with the stock parts and a little more if you have aftermarket UCA’s with more caster built in, but there are definitely limits and all of these cars are a little different- they were from the factory and 50 years later that’s only gotten worse.

On my Duster my A-B measurement is 0. But I run SPC adjustable UCA’s, adjustable struts, QA1 LCA’s, modified bump stops, 1.12” torsion bars, etc to make all of that work.

Geometry wise, it’s better to be lowered than at stock height if you’re running radials, but you do have to be able to set a decent static alignment still.
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Agreed. I was actually at 0 with my A-B when it did not have enough camber. I was thinking the SPC uppers would be better but too late now. Thanks again
 
Just an FYI. When you are setting up the alignment settings , the numbers are at " static" height. The car is sitting still.
Dynamic alignment is like a static tire balance compared to a dynamic spin balance. Dynamic alignments are done on upper class road race and Formula 1 type cars.
When you are driving down the road the suspension is cycling from compression and rebound and as the car moves up and down, so do all the alignment readings.
There is a range of alignment settings that are "within spec". You want your alignment to stay within specs as much as possible based on your driving style and road conditions.
Factory alignment specs are determined using factory spec sized tires and stock spec alignment components. If you change anything eg.. tire size, control arm length, ride height, the driving specs will change and could be out of"spec" range when driving.
Remember that the car manufactures generally also specify a full tank of gas, and at minimum drivers weight in the car before setting the alignment.
There can be several hundred pounds in suspension load difference if you do not take this into account when you have your alignment done.
 
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