I'm going to stick to my guns on using cross as an adjustment tool in this case for stagger. Unfortunately w/ the spec tire, I know that we cannot get the stagger numbers (that the Legends track width combined w/ the sharp radius corners and nearly nonexistant banking that our local track has) to make the car "stagger neutral". When I look up the effects of cross and the effects of stagger the two have a very linear relationship w/ handling symptoms causing the car to be imbalanced.
Corner entry oversteer - excessive rear stagger/insufficient cross (plus several others, some relating to mechanical problems, others alignment or improper springs/tire pressures)
Mid-Corner oversteer - excessive rear stagger/insufficient cross (plus geometry problems, spring rate, and mechanical problems as well as alignment and driver faults)
Corner exit oversteer - excessiver rear stagger/insufficient cross (plus pressures, spring rate, geometry and alignment problems)
Understeer is generally the same, with main causes of entry understeer being more mechanical and geometry related, but mid-corner and exit directed more towards cross/stagger issues.
(information paraphrased from Steve Smith's Trackside Tuning Guide)
If your taking care to keep the ride heights the same while making cross/spring changes, your alignment should not be affected (within reason) because the frame rails are still at the same height relative to the rest of the suspension and the contact patches. Change of alignment at the track could happen just as easily while changing a spring as while changing cross. Measure ride heights before making a change, adjust, and recheck.
"The Crossweight Percent"
Having an excessive amount of crossweight percent, or bite as it is referred to in dirt racing, causes too much weight to be supported be the left-rear and right-front tires and can cause a car to be tight in, through the middle, and off the turns.
Running a crossweight number that is too low is a distinct indication of a tight car, If a car needs 51.2% cross to have a proper weight transfer, and is only running 48.8% the team has needed to take cross out of the car because the setup was tight.
There is an optimum percentage of weight supported by the cross corners (RF and LR) that will make the car neutral. Remember, a neutral car is not necessarily a winning car. It must remain neutral throughout the entire race.
"Rear Stagger"
Insufficient rear stagger will cause the car to "point" towards the outside wall on exit. There is a correct amount of rear stagger for each track based on the overall tire diameters, track width of the rear tires, the radius of the race track, and the track banking angle.
Too little stagger will cause the car to drive to the right as get back to the throttle and the rear end moves in the arc that has a greater radius than the track at that point. The larger the radius, if drawn onto the racetrack, would probably lead into the grandstands and that is definately not where we want to go.
("The Crossweight Percent" and "Rear Stagger" borrowed from
Circle Track & Racing Technology - Chassis & Suspension Handbook (from the editors of Circle Track magazine))
I'll finish with mentioning that following the INEX rules, one cannot overly change the Moment Center on the front of a Legends car like can be done on a late model, nor is there an adjustable (vertically) panhard bar to raise or lower the rear Moment Center, and springs have a minimum 15lbs difference in spring ratings available for use.
If there was something I could make small adjustments at the track to help balance a car, other than tire pressures, cross and springs, I would be very grateful. Until then I'm only smart enough to use the resources set out infront of me.
(nothing personal SMS just defending the reasoning behind my thoughts with literature)
SMS does have a good point on keeping the same ride height (really try to keep to your notes on ride heights while making changes) and that time in the garage at home generally equals positions on the track come race night!
On avg our Legends car is receiving 8 hrs (+) of maintenance per race session and we have a 40% feature win ratio thus far in '09.