Wheel Wednesday

MC Stanger said:
Put two of one set on the drivers side and two of the other set on the passenger side. Nobody will know unless they walk around the car.
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yes and then they will walk back around atleast twice to make sure they are not seeing things.
could be great fun, then when they are not looking turn the car around, when they come back
around they will be confused again :) Cruel really, but quite amusing.
 
67 AGAIN said:
A little survey for wheel Wednesday.
I think I know what the result will be but will get it confirmed.

I have two sets of wheels for my 06.
-07 to 09 GT500 wheels
-2010 GT500 wheels

I’m currently running the 2010 wheels because tires on them are newer and more rubber.
Have used the 07-09 wheels for track days in last few days.

Which ones do you think look better?

07 - 09 wheels?

View attachment 51994

2010 wheels?

View attachment 51995
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I think the 2010 ones suit the colour scheme more.
 
67 AGAIN said:
Toe out most common cause for that type of wear.
Where the front wheels are spread open toward the front.
Pot holes, driving over curbs or rough railway crossings can all cause that condition.
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I was thinking it was the factory negative camber that would put more loading on the inside shoulder and cause wear like that.

Interesting, I'll have to get the alignment looked at when I'm in for the spring oil change. Thanks Marc!
 
That’s partly true, Mike.

But having a toe out condition as well as negative camber accelerates the wear by a lot.
It’s a double effect.

It’s a setup that would be desirable on a road course race car.
It makes for quick response, or initial bite, on turn in, but burns through tires.
The wear can be so bad that, in your case, you could go through a set of tires just by driving from Ontario to St-John.
Enough toe out with negative camber and you would get here and need a new set of front tires.

On other hand, negative camber with a touch of toe in (meaning slightly closed toward the front) can manage the wear quite well.
This still gives you good coefficient of traction through turns with the negative camber but having slightly less of that quick responsiveness on initial turn in is the trade off for having much better front tire wear.
In the end, a better setup for street driven cars.
Or, maybe I should say a better setup to get good tire wear on street driven cars.
 
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I melted a set at the track the same way.
At the time settings were Ford recommended Track setting for my car
came with insert to tell you what setting for optimum use.

3rd session, I was sliding all over the place and going much slower
Came in checked over car, couldn't find anything, ran my hands along inside of
tires and almost cut them on wire. not good,
glad I had trailer not safe to drive home.

Sucky part, took me 10 days to get replacement set.
After that, I went to a friends, we spent 3 hours setting toe and camber
Aiming for optimal performance and wear, we got it, tires wore more even
maybe not quite as fast at track, but still very good and actually did my best time
with these settings.
 
When I got the 17 the first tires (came with Good Years) wore out bad on the inside like the picture above while on the front. Still had 7mm thread but inside was smooth. Alignment was "in spec" they said at the dealer. Next set was BF Goodrich Comp 2. Watched them gradually do the same.

When I checked online I found out the model has no front camber adjustment from the factory. Camber bolts or plates were what others used mainly for lowering or track. Maybe they built the car to sit right for the heavy V8 but the lighter 2.3 loads different. Anyway when it came time for the third set of tires I bought a "Whiteline KCA416 16mm Adjustable Camber Bolt Kit".

Went to CDN tire and got a magnetic dial level. With the car sitting level in the garage and the magnetic dial level on the wheels (used angle iron to span the rim edges flat) I replaced the stock bolts with the camber bolts and set both sides 1 degree positive on the dial. When I go to the shop now for any alignment I tell them they can touch the toe in only and I get a report of the changes but never to touch the camber. Now on my second set of tires since the change wearing even across the threads. Handling seems good with no pulling or drift. Pirelli’s now. Little more confident the next set could be Michelin’s.

Certainly not Ford certified but doing the job.

Camber.jpg
 
All Mustangs come out of factory with negative camber.
In fact, most cars do.
All Fords anyway.
This is safe and good for going around curves.
Because when turning, the center of gravity makes the car lean to the outside.
Negative camber maximizes the contact patch of the outboard tires during this leaning period.

I use plural for tires here because the S550 also has negative camber on the rear wheels and it’s actually more aggressive than the front negative camber.
And it gets even more aggressive if the car is lowered.
This is a big factor in making the IRS a better handling setup than a solid axle, where the camber is neutral or no camber either way.
And the toe is adjustable on the rear of the S550 with a toe link on each side.
The way the geometry works back there, moving the rear toe affects the camber somewhat, which is not the case in the front.

Ok, back to the front.
It is entirely possible, Mike, that your 2017 was within Ford specs but still terrible for front tire use and I can explain.

What I said in the previous post works, and it was the way factory settings were prescribed on the S197.
Negative camber in the order -0.4 to -0.8 degrees, but accompanied by recommended toe in in the order of 0.02 to 0.06 of a degree.

(With negative camber, the toe in acts to pull the contact patch inward and makes it roll flat while moving forward resulting in even wear.

On the other hand, toe out acts to pull the contact patch outward and make it roll on the inside shoulders, leading to accelerated inner wear.)

And these factory settings have + or -tolerance on each side of the recommendations.
So the camber could be as aggressive ad -1 and the toe in as little as 0.01 or even neutral and it will still be within factory specs.
But -1 degree camber and 0.01 degree toe in on each side is still good.

The problem with the S550 is that, for reasons unknown to me, Ford changed the factory recommended settings for the front toe.
Instead of recommending some toe in, the new specs call for neutral toe or zero toe.
The wheel pointing straight ahead.
But they left the camber the same, in the negative numbers.
If set right at zero toe with moderate negative camber, that’s still not too bad for tire wear and gives very responsive steering.
Remember as little as 0.01 degree of toe in on each side has benefits, so one side at 0.01 and the other right at zero would still be good.

The S550 runs into front tire wear issues because of the tolerance each side of the recommendations.
The S550 could be toed out something like -0.01 or -0.02 or slightly higher each side and still fall within acceptable factory tolerance.

As soon as that toe out is present you get that accelerated inner tire wear with any amount of negative camber.
However, the culprit is not the negative camber, it’s the toe out.

The cure is to align the front of your S550 the same way they used to align the S197.
Keep some of that factory built in negative camber and intentionally dial in a bit of toe in, which is the setting that can be adjusted on all Mustangs.

Unfortunately for you Mike, that time you got your alignment checked early on to correct inner tire wear you were served by an individual who did not have enough experience with alignments.
He relied too much on factory recommendations snd the screen on his machine.
It likely was in factory specs, but was also likely toed out.
It still gave him green lights on his screen so he called it good.
If you had inner wear, he should have dialled some toe in to address the issue.
And he should have explained it to you.

The problem with positive camber is that, in a turn, the weight transfer to the outside puts a huge amount of stress on the sidewalls of the tire and the contact patch wants to roll over itself under the car.
This takes away a lot of grip and stability.
When the car is flat the top of the tire is leaning out.
This condition gets worse when you turn and additional weight and external inertial pull gets added to the equation.
All the forces are conspiring to buckle the tire under the car.
In today’s modern cars and speeds we can travel at, I would consider that unsafe.

I would suggest you give your car back its factory negative camber.
It can be conservative, 0.5 or 0.4 degree of negative camber each side.
Some cars come out of the factory with as much as 0.9 or even 1 full degree of negative camber each side.
And ignore the factory recommendation that your toe be zero, and intentionally dial in a bit of toe in for good tire wear
Something like 0.03 or 0.04 degree of toe in each side.

You’re going to have a much better handling and safer car, and you won’t see much difference in tire wear.

I apologize for length but I see the interest, and it’s a good conversation to have.
 
I post for reference bellow a shot of the alignment of my S550 in 2020.

You can see I run pretty agressive negative camber for a street car but my front tire wear is not bad because I make sure I have some toe in dialled in instead of the factory recommended zero toe.

1.4 degree negative camber each side with 0.04 degree of toe in each side.
I was actually aiming for 0,05 toe in each side but the 0,04 mark each side came about quickly and easily so we called it close enough and left it.

You can see the rear negative camber is more than the front at 1.5 on one side and 2.0 on the other.
It’s not adjustable here.
It was achieved with only a half inch drop in the back.
Guys doing 1 plus inch drop in the back likely have more than that.
The factory settings call for total toe in around 0.20 plus, which I have st 0.25.

Final note on positive camber and tolerances around recommended settings.

If you look at the full range of camber that would be considered within tolerance, it goes from -1.5 to 0.0.
So the sweet spot Ford is aiming for is that black mark in the middle, around -0.7 degree of negative camber on each side.

Note Ford does recommend any positive camber.
I’m sure the reasons I touched on above, and mainly the safety aspect, are big factors for that.

2B97B36D-8B79-43AC-B691-50F945021260.jpeg
 
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Problme with most techs and systems,
they will give such a wide difference in specs
and say it is acceptable. After first alignment
I realized this, did my own home work
took it to a shop I knew and I said, this is what I want
( can't remember exact specs at 4am)

He told me to come at 5, they close at 5 lol.
We spent 3 hours setting up car to get what I wanted.
Yes I paid a bit extra.

Point being sometimes you have to tell them exactly what you
want and have someone willing to put in the time to get it
 
Another reason to like this forum, great discussion.

I'll have to get the numbers for mine in the spring and see what I've got and where I need to go.

I got 25,000km out of the front tires, which was 3000km better than what I got out of the rear tires.

Oddly, there was a lot less tread depth left on the rears for some reason. lol
 
SVT4MT said:
Another reason to like this forum, great discussion.

I'll have to get the numbers for mine in the spring and see what I've got and where I need to go.

I got 25,000km out of the front tires, which was 3000km better than what I got out of the rear tires.

Oddly, there was a lot less tread depth left on the rears for some reason. lol
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Stay away from Sport cup 2's lol
8000 most I got no track days.
Went through a set in 5k

normally I put a set on a season.
If I could go to mont tremblan track
I would burn up a set in 2 days.
 
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