Cross weight oval racing driver#
Cross weight oval racing Patch#

One of the keys to obtaining a good setup is using the correct procedure to weigh your race car. In the example at the beginning of the article, this was the problem: a cross-weight percentage that was less than 50 percent, and probably off by at least two percent. On a road course, the cross-weight percentage should be very close to 50 percent, within a half-degree either way, to keep the handling balance similar in a right-hand turn compared to a left-hand turn. This can make maneuvering in traffic difficult, even dangerous. One of the problems with cross-weight is that it will change the handling balance from a left to a right turn. But stagger is not a good idea on a road course or autocross either, where the ideal is 50-percent cross-weight and no stagger. More stagger usually loosens the handling in left turns, so more cross-weight is used to tighten it up. On oval track cars, cross-weight is usually used in conjunction with stagger (where the right rear tire is larger in circumference than the left rear tire) to balance handling. In almost all cases, the loss of cornering performance in one direction is greater than the gain in the other direction. But in a right turn, the opposite occurs and the handling is worse. The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. More wedge means that the car will likely understeer more in a left turn. Cross-weight is also called wedge: If the percentage is over 50 percent, the car has wedge if below 50 percent, the car has reverse wedge. To calculate cross-weight percentage, add the RF weight to the LR weight and divide the sum by the total weight of the car. Cross-weight PercentageĬross-weight percentage compares the diagonal weight totals to the car's total weight. Jacking weight will not alter the left side or the rear percentages. The only way to change the static weight distribution percentages is to physically move weight around in the car. It still pays to be thoughtful about weight placement fore and aft in your car. Additionally, it is much more difficult to change rear percentage much, since rear weight is mostly a design function.

The more power a car has, the more that static weight over the drive wheels helps acceleration off the corners. Rear weight percentage for road racing and autocrossing is less definite. Still, it is a worthwhile goal to strive for 50 percent left-side weight.

Cross weight oval racing driver#

However, many cars cannot make the 50 percent left-side weight percentage due to driver offset. This makes the cornering force balanced from left to right and offers the best performance overall. For road racing and autocrossing, the ideal left weight percentage is 50 percent. Many electronic scales will perform the calculations for you.

The rear weight percentage is found in a similar manner: Add the LR and the RR weight together and divide the sum by the total weight. The left weight percentage is found by adding the LF weight to the LR weight and dividing the sum by the total weight. These tell us all we need to know about the setup relative to the weight distribution. When working with static weight distribution, we use two percentages to analyze the car's corner weights: Left weight percentage and rear weight percentage. The car should be at minimum weight, using ballast as needed to make the proper weight. This means the driver should be in the car, all fluids topped up, and the fuel load should be such that the car makes your minimum weight rule at the designated time-usually after a race.

Cross weight oval racing Patch#

Static weight distribution is the weight resting on each tire contact patch with the car at rest, exactly the way it will be raced. While several different setup parameters could have caused this situation, a likely cause is excessive cross-weight. Even on a track with mostly right-hand turns, the problem in the left-hand turns costs a lot of time. You've tried springs, shocks, different bars, neutralizing the anti-roll bar, and nothing seems to work. If you get the car neutral in left turns, it oversteers in right turns. Why? Picture the following: Your car is really fast in right-hand turns, but understeers in left turns. One of the most important aspects of car setup is the static weight distribution and the cross-weight percentage.