Steering
Sept 11, 2009 6:30:13 GMT 2
Post by ksheppard on Sept 11, 2009 6:30:13 GMT 2
Steering Lock is how much the front wheels' angle changes when you turn your wheel to full lock.
Parallel Steer controls the rate at which the angle between the front wheels changes as steering angle is increased. At high values, acts as toe-in when steering, while at low values, acts as toe-out when steering.
Caster is the angle of your steering movement as seen from the side. It provides some self-centering effect while driving in a straight line. An example of extreme positive caster is a chopper motorcycle where it's steering axis is "laying down" at the angle of the motorcycle's forks. An example of negative caster (never ideal in racing) is the front wheels of a shopping cart. They are being "dragged" behind the steering pivot point, often wobbling around and very unstable. More positive caster dials in more self-centering, which can be a good thing for comfort alone.
An added benefit, and more important, is that caster also affects the camber when the wheels are turned. More positive caster gives more negative camber to the outside wheel when in a turn. This allows the option of less static camber in your setup and using more caster to achieve your ideal camber angle. Just as important is how positive caster effects your inside wheel camber. Your inside wheel will lose some of the negative static camber and possibly even go into a positive camber setting which is ideal for your inside wheel while in a corner. The side-effect of added caster is the ability to reduce your static camber settings. While negative camber assists only your outside wheel in a corner, it has a negative effect on the grip of your inside wheel while cornering and both wheels under braking or acceleration. The more camber you can replace with caster the better your front wheels will maintain grip in all situations.
After changing your caster settings, recheck each of your tire temperatures and make pressure changes as needed. You may need to adjust camber settings as well, usually reducing the amount of static camber you have.
Toe is known as either "toe-in" or "toe-out". It is measured by the angle at which the two wheels are pointing in/out from each other, as seen from above. The "toe" plays an important role in your car's straight line stability as well as its cornering characteristics. A standard passenger car has some toe-in built into the alignment for stable straight line driving. This toe-in is what allows you to let go of the steering wheel in your passenger and the car will continue to travel in a straight line. Toe-in will induce understeer in the corner as both wheels are pushing inwards and against each other to maintain that stability. Toe-out will reduce straight line stability, quite possibly to the point of the car 'wandering' left and right when trying to drive a straight line. Toe-out does offer more grip while turning as the tires are not fighting against each other. It can also be argued that Toe (in or out) adds friction and drag, slightly reducing your top speeds.
The more positive the number, the more toe-in we are dialing into our setup. A negative number will result in toe-out and is what you are wanting in your setup. Generally an eighth to quarter of a degree will do the trick, though I have found myself being more aggressive with this setting at tighter tracks. Of course, I am speaking about the front toe setting. Rear toe-out is never ideal. However, you can use more rear toe-in as another way to settle the rear of the car. Toe-in will get you more stability; toe-out will get you more turn in capabilities but make the car more nervous.
After changing your toe settings, recheck each of your tire temperatures and make pressure changes as needed.
Parallel Steer controls the rate at which the angle between the front wheels changes as steering angle is increased. At high values, acts as toe-in when steering, while at low values, acts as toe-out when steering.
Caster is the angle of your steering movement as seen from the side. It provides some self-centering effect while driving in a straight line. An example of extreme positive caster is a chopper motorcycle where it's steering axis is "laying down" at the angle of the motorcycle's forks. An example of negative caster (never ideal in racing) is the front wheels of a shopping cart. They are being "dragged" behind the steering pivot point, often wobbling around and very unstable. More positive caster dials in more self-centering, which can be a good thing for comfort alone.
An added benefit, and more important, is that caster also affects the camber when the wheels are turned. More positive caster gives more negative camber to the outside wheel when in a turn. This allows the option of less static camber in your setup and using more caster to achieve your ideal camber angle. Just as important is how positive caster effects your inside wheel camber. Your inside wheel will lose some of the negative static camber and possibly even go into a positive camber setting which is ideal for your inside wheel while in a corner. The side-effect of added caster is the ability to reduce your static camber settings. While negative camber assists only your outside wheel in a corner, it has a negative effect on the grip of your inside wheel while cornering and both wheels under braking or acceleration. The more camber you can replace with caster the better your front wheels will maintain grip in all situations.
After changing your caster settings, recheck each of your tire temperatures and make pressure changes as needed. You may need to adjust camber settings as well, usually reducing the amount of static camber you have.
Toe is known as either "toe-in" or "toe-out". It is measured by the angle at which the two wheels are pointing in/out from each other, as seen from above. The "toe" plays an important role in your car's straight line stability as well as its cornering characteristics. A standard passenger car has some toe-in built into the alignment for stable straight line driving. This toe-in is what allows you to let go of the steering wheel in your passenger and the car will continue to travel in a straight line. Toe-in will induce understeer in the corner as both wheels are pushing inwards and against each other to maintain that stability. Toe-out will reduce straight line stability, quite possibly to the point of the car 'wandering' left and right when trying to drive a straight line. Toe-out does offer more grip while turning as the tires are not fighting against each other. It can also be argued that Toe (in or out) adds friction and drag, slightly reducing your top speeds.
The more positive the number, the more toe-in we are dialing into our setup. A negative number will result in toe-out and is what you are wanting in your setup. Generally an eighth to quarter of a degree will do the trick, though I have found myself being more aggressive with this setting at tighter tracks. Of course, I am speaking about the front toe setting. Rear toe-out is never ideal. However, you can use more rear toe-in as another way to settle the rear of the car. Toe-in will get you more stability; toe-out will get you more turn in capabilities but make the car more nervous.
After changing your toe settings, recheck each of your tire temperatures and make pressure changes as needed.