///NEM3SES
03-18-2009, 11:31 AM
Hey guys since I just aligned my M3 and my family is in the tire business, I thought I'd start this thread to help us all gain a little knowledge on the subject and share our specs (be advised I'm still an novice when it comes to alignments lol)...
Why should you align your car?
- adjusting the angles of your wheels/tires allows better handling/cornering
- keeping the tires "in spec" helps prolong tread life/better tire wear
- you eliminate car pull to either side
- helps eliminate steering wheel off centered
http://www.davistirepros.com/images/Stock%20Photos/alignment.gif
CAMBER
-negative camber improves grip when cornering.
This is because it places the tire at a more optimal angle to the road, transmitting the forces through the vertical plane of the tire, rather than through a shear force across it. Another reason for negative camber is that a rubber tire tends to roll on itself while cornering. If the tire had zero camber, the inside edge of the contact patch would begin to lift off of the ground, thereby reducing the area of the contact patch. By applying negative camber, this effect is reduced, thereby maximizing the contact patch area.
(this is why we run negative camber on our cars!!!)
Conclusion: the higher negative your camber settings are, the more grip youll attain on the your turns, however for daily driving too much negative camber will wear your tires FAST!!!
TOE
In a rear wheel drive car, increased front toe in (i.e. the fronts of the front wheels are closer together than the backs of the front wheels) provides greater straight-line stability at the cost of some sluggishness of turning response, as well as a little more tire wear as they are now driving a bit sideways.
With four-wheel independent suspension, the toe must also be set at the rear of the car. (which is why most of us set slight negative toe only in the rear). Toe settings at the rear have essentially the same effect on wear, directional stability and turn-in as they do on the front. However, it is rare to set up a rear-drive race car toed out in the rear, since doing so causes excessive oversteer, particularly when power is applied (IE: Never go TOE out!!)
CASTER
The purpose of this is to provide a degree of self-centering for the steering - the wheel casters around so as to trail behind the axis of steering. This makes a car easier to drive and improves its directional stability (reducing its tendency to wander). Excessive caster angle will make the steering heavier and less responsive, although, in racing, large caster angles are used to improve camber gain in cornering.
My conclusion: Think of a chopper motorcycle, the angle of the front axle of the front tire allows the bike to stay in a straight line at high speeds, but it also makes the bike turn like **** lol. On the other side, street bikes can turn on a dime, but do not have as much stability on the straight aways as a chopper (theoretically) woud... so if your front steering feels like you have alot of play maybe adjust your caster more (+)
Finally share your specs:
2003 M3
Drop 13.3" F 13.5" R
FRONT
camber: -1.5
caster: n/a
toe: -0-
REAR
camber: -2.0
toe: -0-
*impressions: steering wheel is straight and turning handling is excellent, however steering feels a little loose. I think Ill add a just a little toe in in the rear and more camber in the front (maybe -1.7) and adjust the rear to (-1.9). I think I need more positive caster as well to keep my steering wheel from feeling so loose...
*edit* forgot to mention!!!
Rear camber is the hardest to get into spec, and from what I here many of us have problems with this. HOWEVER the solution is
after market lower control arms!!! This will def. get your rear camber within spec and help keep your rear tires from having too much camber wear
LASTLY AND MOST IMPORTANT!!**
-Dont forget to change your RTABS!!!!!
Why should you align your car?
- adjusting the angles of your wheels/tires allows better handling/cornering
- keeping the tires "in spec" helps prolong tread life/better tire wear
- you eliminate car pull to either side
- helps eliminate steering wheel off centered
http://www.davistirepros.com/images/Stock%20Photos/alignment.gif
CAMBER
-negative camber improves grip when cornering.
This is because it places the tire at a more optimal angle to the road, transmitting the forces through the vertical plane of the tire, rather than through a shear force across it. Another reason for negative camber is that a rubber tire tends to roll on itself while cornering. If the tire had zero camber, the inside edge of the contact patch would begin to lift off of the ground, thereby reducing the area of the contact patch. By applying negative camber, this effect is reduced, thereby maximizing the contact patch area.
(this is why we run negative camber on our cars!!!)
Conclusion: the higher negative your camber settings are, the more grip youll attain on the your turns, however for daily driving too much negative camber will wear your tires FAST!!!
TOE
In a rear wheel drive car, increased front toe in (i.e. the fronts of the front wheels are closer together than the backs of the front wheels) provides greater straight-line stability at the cost of some sluggishness of turning response, as well as a little more tire wear as they are now driving a bit sideways.
With four-wheel independent suspension, the toe must also be set at the rear of the car. (which is why most of us set slight negative toe only in the rear). Toe settings at the rear have essentially the same effect on wear, directional stability and turn-in as they do on the front. However, it is rare to set up a rear-drive race car toed out in the rear, since doing so causes excessive oversteer, particularly when power is applied (IE: Never go TOE out!!)
CASTER
The purpose of this is to provide a degree of self-centering for the steering - the wheel casters around so as to trail behind the axis of steering. This makes a car easier to drive and improves its directional stability (reducing its tendency to wander). Excessive caster angle will make the steering heavier and less responsive, although, in racing, large caster angles are used to improve camber gain in cornering.
My conclusion: Think of a chopper motorcycle, the angle of the front axle of the front tire allows the bike to stay in a straight line at high speeds, but it also makes the bike turn like **** lol. On the other side, street bikes can turn on a dime, but do not have as much stability on the straight aways as a chopper (theoretically) woud... so if your front steering feels like you have alot of play maybe adjust your caster more (+)
Finally share your specs:
2003 M3
Drop 13.3" F 13.5" R
FRONT
camber: -1.5
caster: n/a
toe: -0-
REAR
camber: -2.0
toe: -0-
*impressions: steering wheel is straight and turning handling is excellent, however steering feels a little loose. I think Ill add a just a little toe in in the rear and more camber in the front (maybe -1.7) and adjust the rear to (-1.9). I think I need more positive caster as well to keep my steering wheel from feeling so loose...
*edit* forgot to mention!!!
Rear camber is the hardest to get into spec, and from what I here many of us have problems with this. HOWEVER the solution is
after market lower control arms!!! This will def. get your rear camber within spec and help keep your rear tires from having too much camber wear
LASTLY AND MOST IMPORTANT!!**
-Dont forget to change your RTABS!!!!!