This diagram illustrates the...
This diagram illustrates the action and reaction of antidive forces. The braking force tries to rotate the spindle in a clockwise direction (right front viewed from the outside). As the car tries to dive, the angle of the control arms, from this view, acts to try to rotate the spindle counter-clockwise. This is how antidive works.
Once the setup has been balanced and the shocks are chosen, we need to evaluate our turn-entry characteristics. Brake bias is a very important influence at this segment of the track. We do not want to try to solve turn-entry problems with the brake bias. We just need to make sure the car stays neutral in handling when the brakes are applied.
Brake bias influence can be easily determined by entering the corner with medium to heavy braking first and then entering with light braking to see if there is a difference. If there is, try to adjust the brake bias to eliminate the condition.
Once you have made the entry good, check to see if the adjuster is centered. If it is too far to one side, then changes to the brake master cylinder sizes and/or the pad compounds may need to be made in order to solve the problem while maintaining a centered bias adjuster. Off-centered adjusters can be very inconsistent.
A trick that was developed...
A trick that was developed a few years ago and is still not well known is to stagger the heights of the rear trailing arms to help create rear steer when using a pullbar third link.
In situations where the exit portion of the track provides less traction and/or the corner is more flat, we may have the need to develop more rear traction upon acceleration. Just giving the car more rear traction does not help us if the car becomes too tight in the middle of the turns.
We must develop ways to create more rear traction on acceleration only. There are ways to do that without changing the handling at other points around the racetrack. One way is to have a rear-spring split, where the right-rear (RR) spring has less spring rate than the LR spring. This creates more crossweight as the car squats on acceleration.
Another way to gain bite, which we have described in the past, involves the use of a spring-loaded pullbar that allows a certain amount of rear-end rotation to steer a car equipped with different-length rear control arms. As the rear end rotates on acceleration, the left wheel moves rearward more than the right wheel, creating a slight amount of rear steer to the left.
As the link extends, the rear...
As the link extends, the rear end moves back, but the left side moves more than the right side, creating rear steer to the left that will tighten the car.
Antidive and antisquat are mechanical influences that can help our transitional phases of entry and exit. Antidive helps prevent sudden nosedive on entry by mechanically resisting the downward motion of the suspension using the rotational forces created through braking.
As the brakes are applied, the caliper grabs the rotor and the motion of the wheel/rotor tries to rotate the spindle. This force is resisted by the ball joints (BJ). The upper BJ is being forced in a forward direction, and the lower BJ is being forced in a rearward direction.
If, from a side view, we arrange our arm angles correctly, then the upper BJ would need to move to the rear and the bottom BJ would need to move to the front as the car dives. Since the antidive forces are in the opposite directions, there is a serious resistant force to dive preventing the front suspension from moving quickly.
Aero downforce is the result...
Aero downforce is the result of the creation of low pressure zones under the engine compartment.
The amount of resistance is directly related to the degree of sideview angle we put in our control arms. The left-side suspension usually is designed with about half the angle of the right side in a conventional design. For the big bar, soft spring setups, teams often introduce prodive into the left-front suspension to encourage rapid dive on entry to get the left front down quickly.
Antisquat results from the third link trying to straighten out, or become more horizontal, as the car accelerates and the rear end desires to rotate. The more third-link angle you have, the more antisquat there is. Lateral movement of the third link can change the placement of added load among the two rear tires that results from acceleration.
A small amount of pressure...
A small amount of pressure differential can create a lot of added "load," which increases the front and/or rear traction.
The very last thing you need to worry about is your aero package. I'm not saying this is not important at some level, but on short tracks, I would stress that aero downforce is overrated in most cases.
I say that with confidence because I have gone up against more aero-efficient cars with setups and body configurations that were aero-deficient and still outran them. Still, teams want the most they can get out of their cars. If all of the above nine items are in order, then go ahead with aero tweaking.
Try to understand how aero downforce is created and then configure your car so that you take advantage of every area where you could produce more downforce.
If you've been diligent in maximizing the above 10 areas of most concern, then you are well on your way to a successful season. Remember that success comes in all forms. Advancing your finishes over last season is a good step. Don't think that just your setup will lead quickly to Victory Lane. Improve your finish, learn how to win, and then, at the right moment, you'll find yourself holding the checkered flag.