A well designed layout of...
A well designed layout of shock rates keeps a car's attitude in balance on entry, through the middle, off the corners, and enhances the setup. Solve the basic handling problems before trying to assist the setup with the shock package.
The basic setup on our race cars can be further improved by the proper selection of shocks at the four corners. Once all of the basic handling parameters have been sorted out, the car is getting through the middle well, and the tire temperatures look good, we can then-and only then-experiment with different rates of shocks to try to further enhance the entry and exit performance.
Too many teams try to solve basic handling problems with different shock rates or even different brands of shocks. We have learned over the past decade that using shocks to overcome mid-turn handling problems can be frustrating and futile.
The mid-turn handling problems can affect entry and exit performance, which is exactly why we always solve the mid-turn problems first. Anyone who tries to tell us different shocks can improve mid-turn handling is not being honest. The rare exception is when we are trying to overcome rough track conditions, mainly related to dirt tracks, where a different rate and build of shock will allow the tire to maintain more constant contact with the racing surface all the way around the track.
By looking at the angle of...
By looking at the angle of the left-front wheel as the car negotiates the turns, we can tell it is very tight. Shock changes will not solve this problem, only proper changes to the base setup and/or geometry of the car.
We will analyze each corner of the car and see where we might have been crutching the car and where we can use shocks to our advantage. Sometimes we can use one corner to effect a change, and there are times when a combination of corners has a better effect.
The left-front (LF) corner of the car is similar to the left-rear (LR) corner in that it does not move vertically much as we turn laps on asphalt. On dirt, we see more movement due to the setups used to gain bite on the drier and slicker tracks. The most movement either way comes when we are braking into the corner and when we accelerate off the corner. These two movements, compression on braking and rebound on acceleration, can be utilized to our benefit.
What usually happens is that we might try to solve a "loose off" condition by changing the rebound rate of the LF shock or a "tight in" situation by changing the compression of the LF shock. Entry problems can usually be traced to poor alignment of the rear end or front steering problems. Making drastic changes to solve entry problems with shocks is not the first consideration. We need to look at our alignment first.
Using the look-and-see method,...
Using the look-and-see method, so to speak, we know this car is very loose. The direction the car is going compared to the pavement lines in the track surface tells us this guy needs help with the basic setup. Dirt trackin' on asphalt will not get the job done over the long haul.
For corner exit, increasing the rebound resistance at the LF to "tie down" that corner will decrease the upward movement of the LF suspension, but weight is still being lifted off that tire. If there is an aero push due to excess movement of the LF suspension, then increased LF rebound may be a positive change for the aero effect. It might also tighten the car off the corner, which could cause more of a push.
On initial acceleration off the corner, a stiff rebound shock at the LF will momentarily put more weight on the right front (RF) and LR corners, causing an increase in the crossweight percentage, which tightens the car. On the other hand, if we decrease the rebound at the LF, we will de-wedge the car as well as create a possible aero push condition.
We can see where changes to the LF shock in most cases causes opposite effects in different areas. The best scenario is to take the middle road at the LF and not go too far in the direction of either high or low rebound and compression rates.
When we have corrected all of our setup problems, we can enhance the entry characteristics of the race car by utilizing the RF shock. We often try to control excess movement of the RF corner with a high-compression shock, especially over the past few years, where softer spring setups are more common.