Measuring ride height

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Another old school drag trick to level the front, was to raise the left front a little higher, in relation to the drivers weight when he/she were in the car. Yep, to each there own.
Happy Moparing dudes.
 
Why were the super stock springs higher on the right? It pushes the left front lower. Mopar knew a few things as well!
 
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Missed the point! Maybe, every action has an opposite and equal reaction that must be considered. Engine torque counteracts that. Raise the left side front and you unload the left rear. The guys from Mopar were racers and spent lots of time developing these items, seems some folks forget this. Not to say they may have missed something with more modern parts available today, but their work was pretty solid.
 
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72bluNblu said:
If you run radials, using the factory specs for alignment and ride height will not give you the best performance.
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I've seen the "Skosh" chart that provides recommended Camber, Caster, and Toe numbers when using radial tires, but this is the first time I've seen mention of the ride height no longer being ideal. What you're saying makes complete sense though. So would the preferred ride height for best handling be higher or lower than the factory bias ply numbers? And by how much?
 
Keystone said:
I've seen the "Skosh" chart that provides recommended Camber, Caster, and Toe numbers when using radial tires, but this is the first time I've seen mention of the ride height no longer being ideal. What you're saying makes complete sense though. So would the preferred ride height for best handling be higher or lower than the factory bias ply numbers? And by how much?
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I’ve mentioned it before in some of the more technical threads on handling.

As for the ride height for ideal handling, it’s lower and by a lot. The best camber curve happens when the control arms are roughly parallel to the ground. By the factory method of measuring that would be an A - B of 0, which is a 1-7/8” drop. There’s more to it than just that camber curve of course, the lowest CG is also usually best for handling, same for the roll center. You do have to watch other things though like bump steer, and the amount of available travel left.

Now, that 2” drop may not be the best height for handling on your car, because in order to lower your car that much successfully you need much larger torsion bars, you need to ditch the factory bump stops, you’ll likely need shorter shocks, and at least offset UCA bushings to pull of a decent alignment, but probably more like tubular UCA’s to get good numbers.

But lower by any amount that your particular set up will tolerate will be an improvement. Mopar Muscle did a geometry analysis on a 1” drop for their article about using FMJ spindles if you want to take a look at some actual numbers. The article is about the geometry differences between using 73+ A body vs FMJ spindles, but they did a full geometry plot for both the stock and FMJ spindles on a car lowered 1” from factory. The numbers are pretty good even at that height. Now, you’d still need some other changes, larger torsion bars etc, but nothing as radical as what would be needed for a 2” drop.

Swapping Disc-Brake Spindles - Mopar Muscle Magazine
 
No 1/8 of difference A-B, of course 0 is the target when correctly measured. At what cost? It has been now been posted! Drop it low and you now have mush! Now you have to put the biggest bars you can find just to keep your slant from bottoming, remove the lower bump stops and modify everything else. Now both ball joints are at maximum operating angles to boot. That would not be my approach unless I was looking to build something more than a street pounder that drives nicely. There are always give and takes. Venture to bet most want a nice driving street pounder not a canyon carver or F1 car. JMO!
 
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1969383S said:
No 1/8 of difference A-B, of course 0 is the target when correctly measured. At what cost? It has been now been posted! Drop it low and you now have mush! Now you have to put the biggest bars you can find just to keep your slant from bottoming, remove the lower bump stops and modify everything else. Now both ball joints are at maximum operating angles to boot. That would not be my approach unless I was looking to build something more than a street pounder that drives nicely. There are always give and takes. Venture to bet most want a nice driving street pounder not a canyon carver or F1 car. JMO!
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Yup, that's just your opinion, an a misinformed one at that.

  • Lowering the car has no effect on the spring rate
  • Cars with slant6 bars will bottom the suspension straight from factory ride height. So will cars with V8 bars. I've had both, they both bottomed easily, and they do not "drive nicely"
  • The ball joint angles work just fine, I've run well over 80k miles on between my Challenger and my Duster, both riding that low, and have yet to wipe out a single ball joint. Tell Ehrenberger to pound sand with his "ball joint overangling" BS and publish the geometry numbers.

My cars spend all their time on the street and drive just fine. If you set up the suspension properly, you can fix all of the factory suspension design shortcomings that come from running radials on a car with suspension that was originally designed for bias ply's. Using the factory geometry and running radials simply doesn't give you a good handling car. There's a reason so many of these cars end up wrapped around telephone poles, and it's not because they "drive nicely".
 
Yes, they are unibody, but they were NOT built with exacting precision. I've measured the fenders and you'll be close, but I would rather measure the true relationship between the LCA and frame RAIL.
 
A question was asked by keystone if you run radial tires what would be your ride height higher or lower compared to factory specs
 
downsr said:
A question was asked by keystone if you run radial tires what would be your ride height higher or lower compared to factory specs
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I answered that with regard to the suspension settings in post #31 above.

Beyond that I’m not sure exactly what you’re getting at. Just changing to radials doesn’t change the ride height unless you also changed the tire height with the new tires, but that doesn’t really have anything to do with bias ply’s vs radials. If you want to adjust your suspension so the geometry works better with the properties of the radial tires, you would lower the ride height from the factory specs like I explained above. But again, lowering the car also has other consequences, so unless you’re also prepared to install larger torsion bars and offset UCA bushings at the least you may not want to lower the car at all. Riding around on the bump stops all the time is worse than having a less than ideal camber gain curve.

Suspension settings and geometry are ALWAYS a trade off, you have to weigh the consequences against the gains and decide what’s worth it for how you use the car.
 
Tire diameter wont change ride height. It will change ground clearance but not ride height. that is why it is measured the way it is measured.
 
Bodyperson said:
Tire diameter wont change ride height. It will change ground clearance but not ride height. that is why it is measured the way it is measured.
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Well, if you really want to split hairs, the factory procedure is called "measuring front suspension height", not ride height. In fact, the FSM doesn't reference ride height at all, only suspension height.

Probably because the ride height changes with the tire height using the factory method, and there were different tire options available from the factory. Sorry, but if you install 26" tires in place of 24" tires, you've raised the ride height by 1". Now, using the factory method of measuring the suspension height nothing changes. But the height of the car from the ground certainly does.

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72bluNblu said:
Well, if you really want to split hairs, the factory procedure is called "measuring front suspension height", not ride height. In fact, the FSM doesn't reference ride height at all, only suspension height.

Probably because the ride height changes with the tire height using the factory method, and there were different tire options available from the factory. Sorry, but if you install 26" tires in place of 24" tires, you've raised the ride height by 1". Now, using the factory method of measuring the suspension height nothing changes. But the height of the car from the ground certainly does.

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Correct. I confused suspension height with ride height.
 
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