How a zero toe car drives proves nothing about what is actually happening to the toe at speed.

Can you explain the forces that cause the REAR suspension to toe out at speed?

 

When you set front toe in to zero, the steering will become "darty."
It will want to go wherever it is slightly pointed.
When you introduce toe in, in my case, 1/8" per side, the left wheel is trying to turn right, and the right wheel is trying to turn left. This opposing force keeps the wheels straight.
I can then accelerate to 120 MPH, and take my hand off the wheel, and it tracks straight.
The tires may be scrubbing out a touch, but that toe in is still there.
Therefore, I lean toward a BS on the toe change at speed.

 

Bump steer is all I can think of, but that's a different topic.

 

YES your toe in is still there....but it has not toed out enough to become darty.

You even confirmed by writing:
The tires may be scrubbing out a touch, but that toe in is still there..

And at 120 MPH...is serious doubt that how your steering feels in regards to response has changed. maybe not to the point of major concern or feeling that you have to be cautious...but I bet it does become light in the steering.

And we know nothing about your suspension and what type of bushing are being used, etc....WHICH does MAKE A DIFFERENCE. If it is all new and no play in it....then it is doing what it is supposed to do.

Try having your toe in set at 1/16th" and take it to 120 MPH and come back and let us know how you feel then about this. Your car will drive great at 35 MPH...but we can find the magic number to set the toe in at that when you drive it at 35 MPH and then at 120...your car is darty....thus...confirming movement under speed.

But...regardless of that....no one wants to talk to someone who knows about alignments and ask them. Or even take the time to test this stuff out.

DUB

 

You haven't explained how the toe goes out on the rear, only repeatedly made claims about the front end of a car.

 

YES it does. It is proving movement due to the forces on the suspension.

Set it at '0' toe and drive it at inner city speeds ( 35 mph) and you will be fine...then...take it out on the interstate and see what happens. it will change....unless you have a bullet proof solid suspension. Then see if you need a video to see the change.

The dynamics of what the tires are wanting to do is the same for the front and rear. They want to go outwards...thus...reducing the toe in setting.

Depending on how much play or wear a suspension has in it will effect this change.

I feel you need to call a manufacturer for an alignment rack company and talk with them or take a class in a vocational college. I feel you need to hear it from the people who really know this stuff where all of your questions can be answered.

DUB

 

No, it isn't...

35mph is slow enough that almost any "ballpark" alignment would drive acceptably except for it pulling or the wheel being crooked.




Why? what makes them go outward. You're insistent about something you can't explain. If you can't explain it, then why are you here arguing it as a truth?

 

All the toe in stress is on ball joints. The bushings mean squat.
(Yes, I know worn out bushings shift the arm trajectory).

 

If cars started getting darty at speed, millions of soccer moms would litter the road.

 

I honestly cannot get you to understand even though I have explained it....so... can not fix this.

Then what about tie rod ends and an idler arm...I guess by this philosophy..they are not even in the equation.

You guys have a good day/night. I CLEARLY do not have the time to deal with this. There is a saying that is coming to mind right now.

DUB

 

Psst. Those are ball joints too.

 

You haven't explained why at all. Your posts just say it's a fact without any reason why it happens. To summarize your posts in a sentence- The front of a RWD car does it, it's a fact that it does, and the rear of a RWD car must also do the same.


Since you keep going on about the front end of other cars like the German stuff, I'll now post that my C5 drives just fine in the 140-150mph speed range when set to 1/100" toe-in on the rack. That's 6.5X less than your 1/16" test value or almost no toe-in at all.

Further to the above, lots of places recommend using 0" toe on the C5/C6 chassis for high speed track driving. Some even say to use a little bit of toe out.

Of course, now you're just dragging me off-topic into posting about the front end of other cars with double a-arm suspensions.

Already have.

 

Regardless of how they are made...tie rods ends are NOT called ball joints. Or at least here in the USA.

OHHHH...so when you go to the parts store and buy parts and need all of the front end suspension parts that require grease (excluding bearings).... You call all of them 'ball-joints' because they all have ball joints in them. The person behind the parts counter would correct you.

Look at all of the front end rebuild kits and they say: "Upper and lower BALL JOINTS and inner and outer TIE ROD ENDS.

I see that you are just one of those guys. I can say that in the 30+ years of me doing this stuff you are the only person who calls a tie rod end a ball joint.

The if you already have talked with people then I do not need to deal with you or this any longer...and you should have all of the answers you need. I guess I know what I know and you know what you know.

As for set-up on other cars or how they respond to high speeds...what I feel you do not take into consideration is the frame strength/flex and other factors. Do you take into consideration or did it slip your mind that the tires for a new Corvette are GREATLY wider than that of a C3???

Regardless of how a car is set up...is what it is. But comparing a C5, C6 or C7 to a C3. Is not even fair.

My responses are coming from those guys that I know who do this stuff and from my own experiences. If I am incorrect or you feel that it is all B.S. Then I guess that is it just that.

But what I also know and is kinda odd. And it seems that it is something that GM considered. Is that the steering center link for a 1970 big block ( for example) is muck thicker than the same part for a small block car. This is a FACT. And WHY did GM make it beefier??? I know it has nothing to do with the rear training arms....But I give up on you and this. Some things you just can't fix.

DUB

 

So back to the point Lionel and I are trying to convey.
MILLIONS of cars drive every day without toe in settings changing one bit while operating. If they do, the crap is worn out.
Your a great guy full of great knowledge DUB, but picking apart symantics is not proving anything.

 

Finally we agree. Like I believe I wrote several posts back. IF a car has fresh parts and they are all new then the movement of the toe is more than likely not enough to effect anything.

But..as you wrote....if the crap is worn out.. I guess we agree that what I have been describing DOES come into effect. Depending on the degree of the parts being worn out may or may not cause for a drive ability issue but can cause to the tires to wear out..or heat up.

Also...keep in mind that the C2 and C3 cars have the tie rod ends attached to the spindle BEHIND the center line of the spindle...and NOT in front of it like about all of the cars today with a rack and pinion.

BUT seeing how this is about trailing arms..I guess that design change does not matter.

You guys have a great day/night.

DUB

 

You kept bringing up the German stuff and kept going on about how the front end suspension works.



That's OK. I have given up expecting an actual technical explanation why you think the rear trailing arms on a C3 would be forced to toe out at speed.

Have you given any consideration to the fact that the front suspension and rear suspensions of a RWD vehicle have different forces at the wheels? Any thoughts put into the fact that the front wheels are pulled along by the car while the rear wheels are pushing the car along?


If you're going to throw a comment like this out here, you'd better be able to explain why that makes a difference. FYI, posting "I just know" again isn't an explanation.


So, those German cars you posted about multiple times were running old worn-out junk? No, wait!!!! You claimed they ran a bunch of toe-in from the factory so they could safely drive at high speeds without experiencing unsafe toe-out. Except I highly doubt any factory ships cars with worn out junk suspensions.

So, what one is it???? Toe moves outward a bunch like you first claimed or doesn't hardly more at all like you now just posted? You can't argue a stand, change your mind and yet still be condescending towards me claiming to be right all along.

 

Now throwing in something new??

I'd ask you to explain it, but what's the point? I'll just do it myself.

It's well accepted that the main thing this affects is turning. If you're turning and the front outer wheel hits a bump or some kind of road irregularity, the rubber bushings on the a-arms will tend to allow the arms to push inwards a bit.

With the steering in front of the kingpin, this bushing compression causes the wheel to steer itself outwards a bit, or what is more commonly called under steer.

On the other hand, with the steering behind the kingpin, the bushing compression causes the wheel to steer inwards further, or what is more commonly called over steer.

Both methods work just fine and both are still commonly in use today. Care does have to be taken that the cars with rear steer don't exhibit over steer characteristics that would be considered scary to the average driver. Mostly, the under-steer of a front steer setup isn't nearly as much of a concern.

Now can you quit continually going off topic?

 

So i got 3 more years out of it, and it got sloppy again so i assume the center of the old poly disintegrated.
The good news is i found the cause of the chronic pain i was having (not fun to work on cars in pain). After i studied medicine for a year i learned enough to CURE the chronic pain Chronic pain is pain that won't go away week after week, year after year. Now i heal fast like when i was young (i'm now 68). More info in profile.
The slow healing was caused by fat in my diet clogging up the healing process. Healing requires good blood circulation near the injury. So my normal blood pressure and trim weight provided no clue. Dr's say about 80% of health problems are from SAD(Standard American Diet). So, what could be easier (compared to surgery) than a 10 day test with a healthy diet? Finding a healthy diet took months, and when i did the test, i started to feel better, so now fixing an old car makes me feel young again!

 

So i was able to slide the T/A back with half the stuff still connected half-shaft, strut, ebrake cable, brake hose all still in!
And not a trace of the old bushing, about 3/4 inch of slop

 

the new Energy Suspension bushings fit snug into the TA. had to hammer the sleeve in. BUT i think i see their secret to avoid binding. While the bolt is .43" dia, the inside of the sleeve is .49". So there is .06" slop. i don't think it can bind with 1/16" slop.
my mind is drifting........ i wouldn't mind having one of these:
HNY