Front Suspension Toe-in Setting

[Ron C.]

The Forum FAQ tech data tells me that the toe-in spec for Contours should be -0.34 to 0.00 inches. Of course, a negative toe-in value equals toe-out. This is typical for front wheel drive as the thrust while moving forward under power tends to bring the toe-in toward zero. But also, from what I understand increased toe-out results in decreased straight line stability but enhances steering response. Decreasing toe-out toward zero would then increase straight line stability but reduce steering response. This being true (to the best of my knowledge), when I adjust the toe-in on my SVT would I want to favor the -0.34 setting or set the toe-in to zero? Or would I want to be in between, at, say, -0.17? And which setting extreme might favor maximum tire life?

Note: I have just replaced both lower control arms so ball joints and bushings are fresh. The old control arm bushings were shot, like really shot. Tie rod ends are both very tight.

Thanks.
Ron C.

 

[jimbbski]

I just had to check my toe setting this past week. I was running "0" toe as measured. I am now running just a bit of toe out, about 1/8 of an inch as measured at the tires. Personally if you get it close to "0" you're going to be OK. A bit of toe out is best as the front tires pull the car and will compress the LCA bushing a bit resulting in a dynamic "0" toe setting while driving. This is best for tire wear and fuel mileage. Almost all cars will run toe out for performance handling. I usually run about 1/4 inch toe out on my ITA race car, I even ran toe out on my Mustang when I raced that!

 

[BrApple]

I have noted that having a toe-out setting will make the car follow the ruts in the highway more then having toe-in. Yes with toe-in the steering feels alittle bit heavier but imho, the car tracks alot better. This was done by the shop I had the car aligned at, and they deal with alot of high end cars. I have never noted that there was increased tire wear, etc using a toe-in alignment. After driving vehicles with both alignments I prefer the toe-in alignment.

 

[rexxdoggy]

So, my camber is within spec, but the toe was zero'd out on my car. I'm still eating the inside of the tire. Am I wanting to be at a -.17 toe IN? The whole negative toe in would be considered toe out is throwing me off. I want to reduce the amount of tread wear as much as possible.

 

[CKtour98]

I want to reduce the amount of tread wear as much as possible.

But you want to run 9" wides cambered? lolololollololol silly

 

[striker2]

dont think of it as the "toe in setting", just think of it as the "toe setting" toe in is positive and toe out is negative.

 

[rexxdoggy]

dont think of it as the "toe in setting", just think of it as the "toe setting" toe in is positive and toe out is negative.

MUCH better. So am I looking to do -.17 toe (in essence will be toe out then) like the OP was trying to get in the middle of? Or what's the desired toe setting I would want?

 

[jimbbski]

With stock or OEM type bushings in the LCAs then a bit of toe out is desired. I call toe out "positive" and toe in "negative but that may just be me.
On FWD cars since the front wheels pull the car along they will pull the LCAs forward compressing the bushings slightly which you hope will result in a dynamic "0" toe reading.
Since you can't measure your dynamic toe (The car happens to be in motion to achive it.) the exact correct toe setting for your car is a bit of a set and test and then reset until you find the "right" setting for your car and driving style.

With wide tires you may never get the one best setting but more of a compromise.

One way to test if your setting is close is to note how the car tracks on a straight flat road. Taking your hands off the wheel see if the car tends to track straight, does it drift to one side or the other, or if it hits a bump does it effect the steering. Hopefully your caster is not off by much or that will effect this test. To test that again pick a straight flat road and with the car in 3rd gear add power and then back off, do this 3-4 times. Does the car pull first one way and then the other depending on power on or power off. If it does then your caster is off enough to effect the steering and you should have it checked and corrected.

 

[amc49]

Caster has to do more with steering wheel recentering by itself without driver help, and the force required to move wheel away from the centered position. When you have a car that tends to slightly try to go left or right instead of dead straight, the resistance you feel the wheel give your hand as you keep car dead straight is from caster. The two sides of the car have not neutralized against each other since some other setting has thrown the car's neutral steering position off from being centered on dead straight.

I routinely cure the problems you mention of drifting one way or the other or pulling one way or other by simple outer tie adjustments. By doing that you can shift the steering dead center of the car to be centered over the caster and the car then has a perfectly centered wheel and goes dead straight on the highway. The steering wheel will quit fighting you also.

But then I have never paid for an alignment in 35+ years, I do all my own with a level, string to imitate laser, and a home made toe gauge made up of 2 large carpenter squares and a 48 inch level from Home Depot. Cars drive straighter than an arrow and tires last forever.

One of the best tracking tools available is a puddle of water after rain in an otherwise dry level parking lot. Drive through it dead straight and then get out and look at the tracks left. You can even do 4 wheel alignments using that trick.