This car also has the metric four-link rear suspension system. This would be called a Street Stock or Hobby Stock. As with the dirt stock clip car, this setup is a tight one. Because of the higher g-forces encountered on asphalt, the front and rear roll angles differ by 3 degrees, resulting in an unbalanced setup. We need to match the desires of each end more closely.
To balance this car, we could make these changes:1. Change the front spring rates to: LF = 850, RF = 950.2. Change the rear spring rates to: LR = 175, RR = 2253. Move the dynamic MC to 2.5 inches in height and 5.0 inches to the right of the centerline. This improves the camber change on the RF wheel and makes the front end more efficient to work harder to turn the car.
These changes will make both ends of this car more balanced, and the performance will be consistently fast because both ends will work together.
With the low g-forces, the small moment arm (caused by the MC being located too far to the right of the centerline), and the stiff front springs, this car is unbalanced and much too stiff for dirt racing. We can make changes similar to those in the stock clip dirt Late Model, which include the following:
1. Soften and reverse split the front spring rates to: LF = 750, RF = 650.2. Reduce the rear spring split to: LR = 175, RR = 1503. Raise the Panhard bar to 9/10.4. Move the dynamic MC width 2.0 inches to the left of the centerline.
The changes served two important purposes. By softening the front springs, raising the Panhard/J-bar, reducing the rear spring split, and moving the front MC to the left, we were able to bring the roll angles of the front and rear closer together to better balance the two suspension systems. We have also maintained the rear spring split, which gives us more bite off the corners.
The asphalt Modified experiences much more g-force, not only from the improved grip that the asphalt gives, but also because of the 14-degree banking of the racetrack and low center of gravity that these cars have. Nonetheless, this setup is also very unbalanced.
The MC is too far to the right of the centerline, and the Panhard bar (rear MC) is too low. There is about a 2-degree difference in how far each suspension wants to roll, with the rear out-rolling the front. Here is what we might change to correct the setup:
1. Leave the front and rear spring rates alone2.Raise the Panhard bar (rear MC)to: 10.75/11.75.3. Move the dynamic MC width 2.0 inches to the right of the centerline.
With these changes, the car is now balanced with both ends (suspension systems) wanting to do exactly the same thing in the turns. This car will now turn well, drive through the middle faster, and exit the corner much faster.
As you make these changes, don't forget to change the weight distribution to add more left-rear weight or crossweight percentage. As the left-front tire begins to carry more load, the car will turn better and become loose if cross is not added.