So;your car has already been lowered via the t-bar adjusters right?And you have a bigger Sway bar, right?
You don't mention HD shocks, but you say it's not hitting the stops, so I have to conclude that the shocks are in fact HD, or HD to some extent.
And you say your car doesn't hold a line thru a turn.
And the alignment shop pulled your stuff around to get 5* of caster,right?
So now we get into it;
The alignment specs are for straight ahead driving only, and at the proper ride height, and only apply when both sides of the front suspension are at rest .Think about that for a minute.
The only time this happens is when you are cruising in a straight line on a dead-flat,dead-smooth road. Think about that.
So what's happening the rest of the time?
There's the rub.
The manufacturer has designed his front geometry with several built-in features. Firstly; notice that the upper and lower control arms are not the same length. That means as the the suspension cycles vertically, the wheel leans in and out; and that is called camber change.Camber change is necessary to minimize the contact patch from sliding sideways during a turn when the ride height is different, and changing, from one side to the other. If they did that, they wouldn't last very long.In a moving vehicle, the camber is constantly changing,a bit.But more so when being steered.
Secondly, notice that an imaginary line drawn through the upper BJ and the lower BJ, is not vertical. And notice that, as the suspension travels up and down, the angle of this imaginary line changes a bit. This is called caster change. In a moving vehicle, the caster is constantly changing, a bit.But more so as the suspension cycles up and down.
And then we come to Akerman. When the car is put into a turn, each of the front wheels has to travel a different sized circle To do that, each of them has to be steered a different amount. Mr Akerman designed it to that with just one steering-wheel input; smart man.Think about that. If each is steered a different amount, then each has a different camber, and each may have a different caster, and obviously the toe setting is ridiculously different.In a moving,turning, vehicle, the angles are all over the place,a bit.
Let's stop there, cuz the point has been made.The alignment specs are for a vehicle at rest with the wheels pointing straight ahead. The manufacturer specifies a ride height at which the alignment is to be performed, because he knows that at this ride height, all the ever-changing angles will play nice together, and the front end will do what he designed it to do, and the tires will last a reasonable time period.
Then along comes Brucey, who doesn't know any of this, and he changes the ride height;mistake #1. And then he jacks 5* of caster into it;mistake #2. And then the alignment guy cranks the toe back so the tires don't go up in smoke when the car is traveling in a straight line.That was a good idea; But the mistake(#3) he makes, is; he doesn't check the toe change with suspension travel, and the ensuing bump-steer.He is not required to, so,technically it's not a mistake. Had you known about all this monkey-motion, you might have asked him to check the bump-steer, but you would have suffered the upcharge for it.
Wait;What? What's bump steer? Glad you asked. Bump steer causes a car to travel a different line through a turn, than the one you commanded with the steering wheel.Remind you of anything? I thought it might. Bump steer is caused by the toe change that occurs when the suspension is moving up or down in a turn. In the Chrysler system, this toe change is part and parcel of the design. But the designer knew that, and the front ride height was selected to minimize it or average it out between full compression and full extension. In the factory design they actually did a pretty good job, keeping it to a minimum. But when the car is lowered and the caster is cranked, then the toe-change is maximized during turning as the suspension cycles.
And you have just experienced that result.
Correcting bump-steer is not something easily done.
I was an alignment tech for many years.When I lowered my 68 Barracuda, and cranked caster into it, It took me about 8 hours to correct it. It probably takes a half hour just to check the pattern, after the car is all loaded up on the alignment rack.Then you have to figure out what to do, do it, and take another pattern.That's another hour easy enough, so 1.5 total so far. After 2 or 3 attempts, a sharp guy can get it close.Now you are up to about 4 hours. After that, gains are minimal, but being the kindof guy that I am(no not anal), it took at least 4 more hours to approach the factory design. And you probably won't be interested in paying 8 hours of shop-time! So the best idea is to leave everything where the factory put it. Or put up with the self-steering business.
I suppose I should also tell you that with the car lowered, the soft T-bars, and stock shocks, will allow the suspension on the outside of any sharp enough turn, to settle onto the bumpstop, and you won't even feel it. This is not a bad thing, until you hit a bump in the middle of the turn, with the forementioned messed up alignment.This has put more than a few guys into the weeds. But hey, if you drive a stock-car, you should be able to handle the surprise.
Now, let's take another look at the 5*.
Do you need it? Well if you never spend more than a few seconds of time traveling in a straight line over the speedlimit, then no you don't. 5* is great for straight-line stability, so a long trip makes it easy to fall asleep. And when traveling triple digits, or near triple,Yeah, THAT I notice is much more stable; in fact the car now likes it up there, which I was loathe to go to with the factory specs.
But around town,nah. You will never notice a difference in a power-steering equipped vehicle. I think I might say that going from just 1* to 3.5*, my car might be ever-so-less-likely to follow a slight rut. But that could easily be attributed to a change in tire pressure.
So back to the beginning.
By installing the drop spindles, you can return the alignment to something nearer to stock,and let the Chrysler Engineering work for you.(I mean the original engineering team probably spent hundreds of hours working out the kinks of it.) However, I would still recommend to get your toe pattern at least checked after they are installed.
But of course I just gotta ask why you are so interested in lowering your car that far? It's a 'Doba right? It already looks pretty low,right from the factory.
