Originally posted by neon_duke
Just 'cause he postwhores so much in it. Never put in one post what you can spread out over three or four...
Camber is the angle of the vertical axis of the wheel, measured perpendicular to the centerline of the vehicle. Negative camber indicates that the tops of the wheels are tipped in toward the centerline of the car; positive camber means that the tops are tipped out. They got this wrong in GT3; the camber you adjust is actually negative camber. There is no reason to ever put positive camber on a real race car.
Why should I adjust camber? Typical stock alignment settings call for 0 degrees camber; i.e. the wheels theoretically sits perpendicular to the ground when the car is at curb height. As the car corners, the load is placed most dramatically on the outside front tire. This causes the tire to deform such that the contact patch is no longer firmly planted in the middle of the tread area, but drifts up onto the outside edge of the sidewall, and unloads the inside edge of the tread. Compliance, or give, in the suspension components can amplify this effect. The net result is that the cornering grip of the tire is reduced, and the tire slips.
Adding negative camber to the wheel means the loading is biased toward the inside edge of the tire. Consequently, when the car turns, the outside front tire sits squarely on its contact patch due to the negative camber "correcting" for the cornering load. Grip is increased, and the car will turn more precisely at higher speeds.
Camber can be adjustable at all four wheels, but I personally recommend running more negative camber in the front than in the rear, particularly on FWD or AWD cars. Adding negative camber to the front increases grip, thus decreasing understeer and providing more balanced handling. Subsequently, adding negative camber to the rear will increase understeer.
Too much camber can cause loss of straight line traction for acceleration and braking. In the game, this effect shows up at about -4 degrees.
Caster is the angle of the vertical axis of the wheel, measured fore-and-aft, parallel to the centerline of the vehicle. This influences steering effort and tendency of the steering to self-center, and is not adjustable in GT3.
Toe is the angle of the horizontal axis of the wheel, measured relative to the centerline of the vehicle. Toe-in (positive) means that the wheels are pointed slightly toward each other as the car rolls forward; toe-out (negative) means that they are pointed away from the centerline.
So, do you want to toe in or toe out? To evaluate toe for the front, what happens when you toe out the rear? The car oversteers because the outside, more heavily loaded tire is pointing towards the outside of the corner. This steers the rear outward and brings the back end out relative to the front. Use that fact at the front, and you see that toe out steers the front towards the outside of the corner, which equals understeer.
I don't know whether it is modelled in the game or not, but most cars tend to toe out in front dynamically, when accelerating. So if you already have static toe out dialed into the setup, it just gets worse.
Some people claim that toe out in front makes the car more responsive to turn-in. There's no real theoretical basis for this, though it could have an instantaneous effect before weight transfer loads the outside tire. However that effect would last for fractions of a second. On the other hand, a small amount of toe in at the front helps with steady state cornering, which lasts a lot longer than the moment of turn in.
I usually run zero toe and camber at the rear and about +0.25 degrees toe and -2.0 degrees camber at the front on my street cars.
In the game, I typically run zero to -0.5 degrees toe and -1.0 to -1.5 degrees camber at the rear. For the front I usually run zero to +0.5 degrees toe and -3.0 to -3.5 degrees camber. Of course, I fiddle these numbers a little for each car, but that's a good baseline setup.
Hope this helps.
