The cars that use stock springs have weight jacking screws and a housing welded to the fra
This car started out neutral, but went to proverbial hell. That is why unbalanced setups do not win most races. To be perfectly honest, a short race of 25 or 30 laps can be won by an unbalanced setup. These short runs do not provide enough time for the car to abuse the tires. That said, the balanced setup will still be as fast or faster than one that is unbalanced.
Another point of interest is that for every race car and setup, there are several ranges of crossweight that will cause the handling to be neutral. This is not universally known, but through hundreds of cases, it has been proven that one car may have as much as three ranges of crossweight that will make the car neutral.
For most short-track cars, given a particular vehicle weight distribution, there is a low and a high range of crossweight that will make the car neutral. With the same springs, moment (roll) center locations front and rear, etc., the car will be neutral at, say, 51.2 percent and 58.6 percent. The area in between is "no man's land." The truth is that we can find a certain percentage of crossweight in each range that will make the car neutral in handling.
If there are at least two ranges from which to choose, how do we know which to use? We have found the lower crossweight range works best on the higher-banked tracks of 12 degrees or more. For the lower-banked tracks, the high range works better to provide better traction off the corners under acceleration by increasing the loading on the LR tire. On the high-banked tracks, the banking usually creates enough mechanical downforce to provide sufficient traction so the tires will not lose grip under acceleration.
This is how the weight would be distributed at mid-turn when we use the low range of cross
The very best dynamic (while in the turns) weight distribution is when we have two sets of equally loaded tires at mid-turn. In the low range, the outside tires will be equally loaded in the turns, and the inside tires will be equally loaded as well. In the high range, the RF and LR tires will be equally loaded, and the left-front (LF) and RR tires will be equal. With this weight distribution, we have more equally loaded pairs of tires at the front and rear at either range to provide the most traction available, allowing us to go through the turns as fast as the car is capable of going.
We seek a balanced setup because we need a setup that will provide the best weight distribution at mid-turn. The balanced setup causes the weights to transfer correctly and predictably at each end of the car. Unbalanced setups are highly unpredictable due to weight transfer caused by tire wear or the driver changing lines up and down the racetrack where the track banking is different or the track surface changes its grip characteristics. Handling balance may also change from afternoon (warm) to night (cooler) with an unbalanced setup, whereas a balanced setup stays more consistent.
This is an example of how the weight would be distributed at mid-turn when we use the high
We can predict the best crossweight for a car based on its weight layout, or where the weight is placed in the car. The front-to-rear distribution of weight dictates the crossweight percentage to use. The greater the rear percentage, the more crossweight necessary to run in order to be neutral for each range.
If a car needs 52.2 percent crossweight to be neutral based on the front-to-rear percent, and if the team is running 49 or 50 percent and the car is neutral, the setup must be unbalanced. The setup must be a tight one in which the RF tire is working too hard and the car is tight. Reducing the crossweight will make the car more neutral but won't solve the problem with the unbalanced setup, and the RF tire will continue to do too much work. Even worse, the car will probably be loose off the corner, prompting the crew to make changes that will tighten it, thus intensifying the original problem.
Another interesting phenomenon is that as the applied g-forces change, so does the crossweight requirement for a particular car. The higher the g-forces generated by a car, the more crossweight percentage we need. If our car tends to fall off a lot on lap times over a fairly short run, the g-forces drop off also (less turn speed means less g-force).