Camber vs. Toe and Tire Wear

Posted by DG-FNR, Feb 9, 2005
Handling Tech - 4G63 suspension, steering, brakes, tires, lightweight wheels, bushings, etc.

  1. DG-FNR

    DG-FNR Proven Member

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    From personal experience:

    1) Camber changes the lateral dynamic load on the tire surface. A car with a lot of static negative camber puts more load on the inside edges of the tire. In extreme cases with a wide tire, a lot of static negative can even lift the outside edge clear of the ground.

    The increased load on one part of the tire when compared to another increases wear marginally. If we use the extreme example, if the outer part of the tire isn't touching the ground, it can't wear, can it? :)

    But the total wear rate isn't really accelerated. If we assume the same compound, and we make a rough assumption that a tire of X width at a large camber angle produces the same ground pressure ad a non-cambered tire of half the width, we'd assume that both tires would wear out at roughly the same time. In other words, the tire will wear out a little faster than a non-cambered tire of the same width, but not outragously so.

    2) Toe physically scrubs the face of the tire across the road. (actually, it sets up a permenent slip angle which may or may not involve physical slip... but we can treat it as a scrubbing action) Any degree of DYNAMIC toe (which relates to any static toe in excess of the factory specs) will result in HIGHLY accelerated wear. Toe is a tire killer.

    3) A combination of a lot of static negative camber plus a lot of dynamic toe results in a lot of tire scrub confined to a smaller area of the tire. This combination can kill tires in very short order.

    If you are lowering a car, toe is an immediate priority. The tire wear characteristics of toe are such that the only time you want to drive the car with the toe out of spec is on the way to the alignment rack.

    The tire wear characteristics of camber, however, are much much smaller, and need not be worried about all that much. For reasonable amounts of static negative, the extra camber might even be a good thing, as you can expect better maximum-roll cornering force.

    If the concern is strictly maximizing tire life, then yes, camber is worth correcting. But it is nowhere near as important as toe.

    DG

    Learn: http://autocross.dsm.org/books.html
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  2. jtmcinder

    jtmcinder DSM Wiseman

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    The only front-engine cars with zero rear toe from the factory are those with a solid rear axle.

    Camber does not increase tire wear; it merely focuses it on a smaller area. Toe eats tires because of the constant scrub.

    It is better to have slightly negative dynamic camber than slightly positive; therefore, for cornering, it's better to over-do the static camber settings than to under-do it.

    These points have already been made many times.

    - Jtoby
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  3. L2RTSiAWD

    L2RTSiAWD Moderator

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    Split this off from the faq suggestion thread so I could put the info in the faq section.
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  4. mr D

    mr D Proven Member

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    I must say that i dont agree on all of the things. I am no expert but i do have some ( bad ) experience with my setup.
    The camber can be a big problem because i have a 400whp .... fwd.
    When i put on some gas on the pedal the camber makes sure that there is not much tire contact. When they spin on a small surface than that surface wear way harder. If the tire has a better camber setting it would not spin with that boost level and speed. Making for less wear general and as a bonus more grip while pulling from 0. Since the mot man here say that my tires need to have a minimum of 1mm as the maximum wear point means that the innerpart of my lowered car tire can be a mot error very fast.
    It is not THE reason for me to correct the camber. I want a great stearing and riding car. Witch can put down its power better ( Autronic + ABS sensor controlled traction controll is being installed right now ) . If one is going to mod stuff on his or her car why not make it better handeling too iso of looks only. I do think that a camber correcting set for a lowered car is very usefull. I tryed to ignore it but i cant anymore. Not with this power and the 400 Euro a piece tires.
    So a slight negative camber up front is the best option then, and the rear needs to have 1 degree + camber than the front. I will ask the wheel specialist if they have any info on the toe in of the wheels but less is better, but 0 makes the car an uneasy ride.

    It comes all down to testing then.
    http://www.dsmtuners.com/forums/showthread.php?p=1609465#post1609465
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  5. DSMcrazy3

    DSMcrazy3 N/T DSM Wiseman

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    I must dis agree, when i lowered my car..Like most people i suffered very negative rear camber, my tires would barely make it 2 months before balding.
    I did a homebrew camber kit(4 months ago at least) and i haven't seen any excessive wear since.

    Josh
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  6. jtmcinder

    jtmcinder DSM Wiseman

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    Did you have the car aligned? If not, then you have no actual data and are talking out your ....

    When you lowered the car, you not only increased the camber, you also changed the toe. The rear toed out a lot, in particular.

    When you added the camber kits in the rear, you not only reduced camber, but you also reduced the toe out.

    In the rear, camber and toe are highly correlated. You can listen to those of us who know which of the confounded factors produces tire wear or you can go get your free advice elsewhere. Free country.

    - Jtoby
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  7. DSMcrazy3

    DSMcrazy3 N/T DSM Wiseman

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    Actually i didn't have it aligned i didn't think about the fact that it cause toe out, your right and i apologize

    Josh
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  8. mr D

    mr D Proven Member

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    Ok it is clear that the toe does the most damage. But camber "could" have an affect on it to.
    I will check the front and rear toe. Front will be 0 and rear 1 degree toe in.
    I can check with any alighn company but mostly they will get the numbers from the books. And i think there are better setting for cars that are wayyyyy different from the factory specs.
    Thanks for all the read so far. :thumb:
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  9. jtmcinder

    jtmcinder DSM Wiseman

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    For the last time (this week, at least): toe causes the excessive wear since the tire scrubs all the time. Camber concentrates the scrub on a smaller area, making that area wear faster than if the scrub were spread wider. Camber alone (i.e., with near-zero toe) only concentrates "standard" wear on a small area and, since "standard" wear is minimal, it does not cause any problems.

    Many of us are running 2.5 degrees or more of camber on street-driven cars. Those of us with zero toe have no issues.

    Mods: time to lock this puppy. It is going in circles.

    - Jtoby
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  10. slugsgomoo

    slugsgomoo Proven Member

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    jtoby: You're absolutely right. My camber isn't zeroed out and i have very minimal wear due to the fact that i run zeroed out toe on my car.

    Honestly i'd like to run -2.5* in the front, and about +1 or 1.25* in the rear (to give a touch nicer oversteer- i honestly need to try it and see how that makes the car behave. I've not tried doing something like that with an AWD car before).

    Camber is a good thing, dynamic negative camber is even better. :thumb:
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  11. mitsugsx95

    mitsugsx95 Proven Member

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    Not trying to be a smartass or anything, but why would more rear negative camber give you the tendancy for oversteer? If you have more neg. camber, you will be using more of your tire during cornering, hence more traction. I would think that you would want to modify your suspension, i.e. springs, shocks, roll-bars, to achieve oversteer.

    Also, just to add to the original post, i am running -2 camber in the front with 0 toe and my tires are fine.

    Yet again, camber is fine up to a point.... its toe you have to adjust.
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  12. mr D

    mr D Proven Member

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    I am sorry that i havent read the forums a lot. I am the lonesome tuner. Toe it is i am convinced. I will try the 0 first. You opened my eyes.
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  13. slugsgomoo

    slugsgomoo Proven Member

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    Negative rear camber produces more understeer. Positive rear camber helps to produce oversteer. If you have ever felt how twitchy a car with a LOT of front positive camber (like 5 degrees) feels, you'll understand why.

    There's a suspension tuning faq out there somehwere that talks about what to add, and what to subtract to make certain things happen.

    The best alignment won't help if your suspension isn't up to it. I'm moving my car to full polys and coilovers once fundage allows. :)
    #13
  14. jtmcinder

    jtmcinder DSM Wiseman

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    Go away. Please. You have no idea what you're talking about.

    The only time that I have ever seen a car with anything more than maybe 1 degree of positive camber was right after the teenage driver slid it sideways into a curb.

    I can't imagine what +5 degrees of camber would even look like. My guess is that I would ask the car if it needed to pee.

    - Jtoby
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  15. mitsugsx95

    mitsugsx95 Proven Member

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    Even if you are trying to say NEGATIVE camber instead of POSITIVE.... I still have no idea what you are talking about. None of that makes sense at all.

    As jtmcinder said, I don't even know why you'd want positive camber. There's no good that can come from that... unless your driving on a big log or something.
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  16. slugsgomoo

    slugsgomoo Proven Member

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    I bought a car that had been curbed, and had 1.8* negative caster, and 3.2* negative camber up front. The weird thing was that with the tires that were on the car (utter sh**) it didn't look quite that bad. (maybe 1*) I threw new wheels and tires on that weren't rated @ 480AB, and the car definitely behaved like you would expect a car with that much negative camber. of course, after the new tires i was headed straight for an alignment (and replacement parts :mad: ) ASAP anyway.

    FWIW my point about REAR positive camber *is* correct. A tiny bit of positive (nothing extreme i.e. over 1.25*) will give a bit more oversteer, however it might be a bit twitchy. I haven't gotten to try it yet myself, but i've seen some guys with understeer prone FWD's tweak a bit of positive at AutoX events and do pretty well.

    I would never advocate more than 3* camber in the front, and then ALWAYS negative.

    If i misrepresented what i was trying to say i'm sorry.
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  17. jtmcinder

    jtmcinder DSM Wiseman

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    I'm sorry, too, but I've had some bad experiences on this list with people who have "slug" in their handle.

    Anyhow, anyone who goes all the way to positive rear camber to get a DSM to rotate should be working on the nut behind the wheel, instead. They are probably entering corners too fast. I have my car set up to be pretty loose, but that still means .75 degrees negative in the rear, even with 2.5 degrees negative in the front.

    - Jtoby
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  18. slugsgomoo

    slugsgomoo Proven Member

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    Yeah. Like I said, I haven't gotten to experiment with it yet. Once i get the suspension stuff done on my car I might play around with it, since one of my buddies has an alignment rack, and there's nothing like trial and error. ;) Frankly, I'd guess that a new center diff with a 30/70 front/rear would probably help me out a bit more than trying to bandaid stuff with rear camber anyway. :coy:
    #18
  19. jtmcinder

    jtmcinder DSM Wiseman

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    Who is the fastest DSM autocrosser? Sean Caron aka Tevenor.

    What differentials does he have? Stock.

    - Jtoby
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