Every race car needs a certain weight distribution that is dependent on the front-to-rear weight distribution so that after weight transfer, the load distribution on the front matches the rear. For example, a typical Super Late Model car has a front-to-rear distribution of 51 percent, so 49 percent desires a 50/50 crossweight distribution (zero wedge) if the car is balanced dynamically.
The exact front-to-rear distribution for each car is dependent on the center of gravity height, unsprung weights, lateral g's experienced, and so forth. We cannot tell you what you need for your car, but if you have extra ballast weight to move around, moving it front to rear will definitely change the handling to help make the car more neutral.
Stagger in circle track racing works to help both tires turn the same number of revolutions through mid-turn, which helps the car to be more neutral in handling as power is applied coming off the turns. For road racing, we don't have that luxury anymore. Our tire sizes must be equal side-to-side at the front and especially at the rear. A turn to the left must be equal in all respects to a turn to the right for all kinematics and dynamics settings, and stagger is a part of that rule.
A typical circle track car...
A typical circle track car has a crossweight that is above or below 50 percent. For example, if the RF and LR percentage of total weight is 51.4, then the LR and RR weight percentage would be 48.6. If 51.4 percent worked to make the car neutral in a left turn, then it certainly would not be neutral at 48.6 percent in a right turn.
Many road racing cars utilize special rear differentials that will slip to create a stagger effect. Tuning the degree of slip is an art unto itself, but that is nearly the only way we can adjust for no stagger. The front stagger must also be zero, but if a set of tires are not exactly equal in size, some stagger at the front will be less detrimental to handling (only affecting braking balance) than if we had it at the rear.
Tuning for Different Turns While we stated that all systems must be equal side to side, we will now move forward into fine-tuning the road racing setups by saying that some small differences are allowed in road racing. Every track will tend to have more turns in a certain direction than in the opposite irection.
A track that is run clockwise will necessarily have more degrees of turns to the right than the left, or we would never return to the start/finish line. In fact, on a track that runs clockwise, there will always be 360 more degrees of right turns than left turns.
The greater number of turns in a particular direction can affect our thinking on settings, but the average radius of each of the turns for the same direction is a consideration. For example, if we run a track with 12 turns, with 4 more right turns, we might be inclined to favor the right turns (as to cambers, and so on) to gain overall performance.
That may be a wise decision if not for the possibility of varying radii of the left and right turns. If our left turns are faster and longer and we can gain more speed in those than could be gained in the tighter right turns, then we should set up our cars to favor the left turns so that we will see more overall gain.
The crossweight for a road...
The crossweight for a road racing car needs to be 50 percent. That way, the handling balance will be equal for right and left turns.
To do this, we would probably increase the RF camber, decrease the LF camber, introduce a small amount of rear steer to benefit left turns more (rear-end steering left for traction), and even alter the crossweight percentage to gain favor in the left turns if 50 percent crossweight distribution is a problem.
If you are preparing a former circle track car for road racing, start out with equal settings for both left and right turns. You cannot go wrong with that. Once you get used to that and get some experience and a feel for what the car is doing, try fine-tuning the car to favor the direction of turns where there might be a gain to be had. Oftentimes the handling will be a compromise, so we do the best we can and try to get the handling as close to neutral as possible.
Small improvements show a much greater gain in lap times on a road course than on a circle track. Where we might gain 0.20 second with an improvement on a circle track, the same improvement might gain 1 or 2 seconds on a road course. That is because there are two turns versus 10 or more turns. Don't forget the basics such as alignment, bumpsteer, and Ackermann steering effect. Good luck-you're a part of the wine-and-cheese crowd now.