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ALIGNMENT SPECIFICATIONS
Written 5-20-2002

4-wheel alignment is a critical part of vehicle maintenance. It is necessary for correct handling, even tire wear, and safety. I have had numerous requests to post this this information. The following is the wheel alignment specifications for the my330i vehicle.

I have included the recommended measurements for a lowered E46. Also included are the numbers right after I installed the PSS9 COILOVER SUSPENSION and my current numbers after a final alignment.

At the bottom of the page, you can find definitions of the alignment types.

RED text denotes specifications outside the recommended range.
These specs are for a 2001 330i Sport Package with 18" Wheels.

LEFT FRONT   RIGHT FRONT
OK Range PSS9 Final   OK Range PSS9 Final
-1.1° -0.4° -1.6° -1.4° Camber -1.1° -0.4° -1.4° -1.3°
5.1° 6.1° 5.3° 5.3° Caster 5.1° 6.1° 5.3° 5.3°
0.6mm
0°04'
2.3mm
0°17'
-1.9mm
-0°14'
1.8mm
0°13'
Toe 0.6mm
0°04'
2.3mm
0°17'
1.7mm
0°12'
1.8mm
0°13'

LEFT REAR   RIGHT REAR
OK Range PSS9 Final   OK Range PSS9 Final
-2.3° -1.8° -2.2° -2.2° Camber -2.3° -1.8° -1.9° -2.1°
1.1mm
0°08'
2.3mm
0°17'
2.4mm
0°18'
1.6mm
0°12'
Toe 1.1mm
0°08'
2.3mm
0°17'
2.7mm
0°20'
1.9mm
0°14'

FRONT COMPOSITE   REAR COMPOSITE
OK Range PSS9 Final   OK Range PSS9 Final
-0.5° 0.5° -0.2° -0.1° Camber -0.3° 0.3° -0.3° 0.0°
-0.5° 0.5° 0.0° 0.0° Caster N/A
1.3mm 4.6mm -0.3mm 3.6mm Toe 2.1mm 4.7mm 5.1mm 3.5mm
N/A Thrust -0°06' 0°06' -0°01' -0°01'

As you can see, the PSS9 installation DOES require an alignment. The ride height change and resulting change in toe/camber was drastic enough to noticably affect the handling of the vehicle. I had the toe issue corrected and balanced the higher negative camber in the front wheels. I chose to keep the excessive front camber for handling purposes.

DEFINITIONS
CAMBER     Camber is the inward or outward tilt of the tire (measured in degrees) when viewed from the front of the vehicle. Negative camber is when the top of the tire leans inward. If the top of the tire leans out, that is positive camber. If the tire is straight up, it's at zero camber. Most cars have positive camber.
EFFECTS:
Positive camber reduces steering effort and improves high-speed stability.
Negative camber improves handling and low-speed stability.
 
CASTER     Caster is the position of the wheel in relation to the strut centerline when viewed from the side of the vehicle. When the top of the strut is set behind the wheel center, this is positive caster. Almost all vehicles use positive caster.
EFFECTS
Higher caster angle improves straight-line stability.
Lower caster angle reduces steering effort and improves turning.
 
TOE     Toe is the angle of the wheel in relation to the vehicle when viewed from the top. Most rear-wheel drive vehicles have higher "toe in"; The fronts of the wheels are turned slightly towards each other. This is due to the effect of the tire's drag on the road surface tends to bring the wheel straight.
EFFECTS:
Toe-in improves steering stability.
Toe-out improves turn-in.
 
THRUST
ANGLE
    Thrust Angle is the difference between the driving directions of the front and rear wheels. It is used to align all 4 wheels into unison and is mostly used on trucks and rear wheel drive cars. It should be as close to zero as possible.

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