[thstone]

Originally Posted by cameronzero

i'm gonna go read again, but i remember reading that the car has to be balanced and aligned with 165lbs in the drivers seat to facilitate the best possible handling, regardless of suspension setup. i could be confusing it with the track suspension information i was reading also.

EDIT: if it's factory suspension, you could also be suffering from sag due to the age/wear of the suspension.

Here is a good tutorial on corner balancing: ELEPHANT RACING Tech Topic, Corner Balance

"Corner balancing is the process of shifting the weight carried by each wheel to approach optimal values. Although some weight can be shifted between wheels by physically relocating parts of the car, the corner balance process is focused on shifting weight by adjusting the suspension spring height.

Street cars are rarely corner balanced and typically have no provision for adjusting spring height. That's because their spring rate is relatively low, perhaps 100 lbs/in. With such low spring rates it would take a huge imbalance in spring height to have a significant affect on corner balance.

Performance and race cars may have spring rates of 300, 400, 500 lbs/in and higher. Corner balance becomes much more important due to the high spring rates - small changes in height greatly impact weight carried. Additionally, we are much more concerned with handling and performance with race cars so corner balance becomes very important."

You have to be able to adjust the spring/ride height in order to change the loading of the spring - which almost universally means a "coilover" shock with an adjustable perch. Stock Boxster struts have no such adjustment.