The rate of the shocks for...
The rate of the shocks for compression and rebound should match the spring stiffness you are running. Remember, springs resist compression and promote rebound, so you need more rebound control or rate than compression rate.
It has been found that alignment issues present serious drawbacks to a finely tuned chassis and setup. Alignment issues are defined as: a) rear end alignment, b) contact patch alignment, c) driveshaft to pinion/transmission alignment, and d) engine alignment.
The rear end does not need to be any different in alignment than at 90 degrees to the centerline of the chassis and/or to the right-side tire contact patches. Those patches also need to be in line.
The driveshaft alignment is also critical due to the generation of vibrations and harmonics that are damaging to the bearings and can be felt by the driver. The general rule is that the angles between the driveshaft and both the pinion shaft and the transmission output shaft need to be equal and in opposite directions.
The driveshaft doesn't "know" the view from which these angles are resulting, just that they are equal and opposite. If we have a top-view differential in alignment between the engine (crankshaft and transmission output shaft) and the pinion shaft and they are parallel, then the angle created by that misalignment may be sufficient to provide needed angular differentials.
A 1 1/2 -inch misalignment with a 44-inch driveshaft results in nearly a 2-degree angle at the tranny and pinion shafts. The engine should always be aligned perpendicular to the rear end and/or parallel to the centerline of the car.
If the brake bias is at or...
If the brake bias is at or nearly out of range for the adjuster in your car, it is time to think about different-sized master cylinders and/or different compound brake pads. It is not recommended to run the adjusters very far off center because of inconsistencies that will result.
The setup we choose for our car needs to be arranged so that the dynamics are balanced between the front and the rear suspensions. Each suspension system desires to do its own thing. Components that affect the desires are: the spring stiffness and spring split, the sprung weight it has to handle, and the moment center location.
Each end has its own moment arm length and resistance to roll as well as other factors. The bottom line is that at midturn, each end will want to roll to its own degree of angle. If those desired angles are different, then we term the setup unbalanced.
Unbalanced setups exhibit certain characteristics, such as an unusually high degree of wear and temperature on one tire versus the other tires. The car may or may not be neutral in handling, but the handling will not be consistent. Work to determine if your setup is balanced and then make the necessary changes to bring it into a balanced state.
Another trick that has been...
Another trick that has been used in the past involves mounting the left spring in front of the axle and the right spring behind. When using a pullbar, as the rear end rotates, load is added to the left-rear tire (and the right-front tire) and load is taken off the right-rear tire (and the left-front tire). This increases crossweight percentage, tightening the car.
Once you have evaluated the above and feel fairly confident that the car is set up correctly, you should then work to tune the transitions with the shocks. The overall work that a shock does is to resist the rebounding of the springs and control the rate of compression. Since the spring promotes rebound and resists compression as its properties, the shock's compression rate must be less than the rebound rate.
The amount of difference is directly related to the installed motion ratio of the spring and the spring's rate. A very soft spring would need more compression rate and less rebound rate, whereas a stiff spring would need a lot of rebound rate and much less compression rate.
Shocks affect the motion of the corners of the car and the placement of loads during transitional periods. If one corner of the car is shocked stiff, then, as that corner desires to move in compression, more load will be retained by that corner as well as the opposite diagonal corner of the car. This will happen during the compression cycle only.
If the same stiffly shocked corner is in rebound, less load will be retained by that corner, as well as its diagonal corner, during the rebound cycle only. That is the essence of shock technology related to handling influences. Plan your shock layout by comparing the shock stiffness to the other corners and to the spring stiffness at the corner you are trying to control.