James from P-S-T responded on b-bodies -
correct me if I am wrong but wouldn't it be up and down movement and not fore and aft as the body rolls in hard cornering one side of the suspension is forced down while the other side the pressure/load is released and by having the heim joint it allows free movement and faster response from the k member to control arm? The adjustable portion the rod would effect the fore and aft movement?
them someone else chimes in...
Yes that's what I meant.....I musta boogered it up. I meant that with the addition of the heim joint that that REMOVES up and down movement from the strut rod bushing. Right? The fore and aft would still be there. Although I am sure with yall's bushings fore and aft movement is reduced quite a bit.
The up and down movement I am referring to is from suspension travel. I wasn't talking about body roll, but that force would also be eliminated with your design as well.
Then James comes back again -
I think you and I are taking about the same thing. But I wouldn't say it removes the upper and downward motion. If anything it increases it. It allows control arm free-er movement up and down throughout its suspension travel with less binding. In turn increasing responsiveness in corning situations and allowing for a more planted tire.
The adjustable strut rods do two things
Adjusts caster (Fore and Aft)
Allows free-er movement up and down and the k member point
I dont like the idea of a well - planted front tire. I've got more wieght up from then most ( told you NIKKI was a double-D
There are some flaws in the logic presented to you above. First and most important is to remember that the suspension is loaded in multiple planes. It never is exclusively up/down, fore/aft, or in/out. Because of weight, tire scrub, loading, direction, etc, there are multiple forces pushing the suspension in multiple directions at all times. Yes, there are times when a certain situation moves the load to be more in one plane than another, but it is only the percentage change in direction, not the total load. This is why it is designed in a triagulated manner. A good example of this is why you align a street car with toe in. The simple act of driving down the road pushes all the various components to a position where you want the dynamic motion of the car to produce a zero point in toe to minimize friction and wear. This same priciple applies to the suspension in its entireity in any dorection it is moving.
Additionally, when you look at the way a rod end is constructed, it is to allow a greater range of mis-alignment than what can be achieved with a bushing alone, while reducing the friction within that mis-alignment. As Brad pointed out, there is a sweet spot that the adjustable rods allow you to achieve that a fixed rod may or may not be able to hit. Yes, this can add a bit more caster, which is the optimizing part because you have altered the fixed location of the device, but it is by no means a band aid that allows you to radially crank up the caster as this would introduce binding. FWIW, the fox bodies Mustang guys have been using adjustable struts for decades. It is a pretty accepted practice in the automotive world.
I haven't read through this thread from the begining so I'm not sure what the original focus or question was. The underlying focus before changing any suspension items should be how do you use the car? Chrysler spent a lot of money to produce the design that we have. Is it optimal, no. It is the best reasonable compromise of performance, cost, serviceability, and lifespan. If you use your car in an average way, you can get away with the stock stuff pretty far into the driving range before you reach its limits. I also agree with Brad's conclusion that two big issues with the stock set up are bump steer and soft rates. I would also add range of adjustability as a limitation. But, that shortcoming has evolved with our point of view as our modern cars have evolved.
40 years ago, the Chrysler design was great. Then came radial tires, then revised alignment geometry, then higher rates. Remember, skinny bias ply tires where the norm when these cars were designed. The advent of radials allowed designers a broader range they could work in before unusual wear would occer, so they took advantage of it. Them alignment angles changed which allowed casual rivers to feel more confident. As driver confidence grew, speeds when up, spring rates needed to rise to keep pace. The net results are that we have modern cars with much more agressive alignment specs and much higher spring rates than a classic does in its stock form.
The good news is you can overcome a great deal of the deficit of our older design with just a few changes. An adjustable strut can be a part of this, as can offest upper control arms and bigger t-bars and s-bars. Put these all together and it is entirely possible to get a classic to feel more modern without a radical change in look or function.
