In my last article I discussed the need for balance when considering upgrading the performance of your vehicle. Overall balance is the key to getting the most out of your upgrade dollars in every area with the end result being the finished “ride” that meets your goals.

The thinking that “more power” is always the answer to a “faster car” is not true. If all areas of performance are not addressed equally you will have as an end result a car that will accelerate quickly and be out of control just as quickly, resulting in a potential crash.

We begin performance upgrades with a balanced chassis. This starting line begins at understanding the overall driving goals for the car that we are working on and moving forward from there. Once we have established the end result that is expected we put together a chassis package that reflects these goals and will guarantee the driver predictable chassis response in all driving situations. To retain balance while increasing performance these packages begin with upgrading the springs, struts, shocks and bushings and then move to full chassis upgrades

We always begin with considering the proper center of gravity for the vehicle that is to be modified. This point is critical to our overall planning and drives our selection of spring rates, struts, shocks and overall chassis rigidity pieces. It should be noted here that “lower” is not always better. Many times we see modified vehicles that are simply too low resulting in poor drivability and ride quality as well as less than predictable handling characteristics due to improper steering geometry.

We have found that 1.25”-1.50” overall drop is the optimal ride height for a Mustang. This change in the center of gravity works well within the factory steering geometry and gives an acceptable ride height for street use. We recommend various spring rates which are dependent on the owner’s driving goals and also whether the car is using a stick axle or IRS. Bump steer kits as well as other steering component upgrades are recommended for more aggressive setups.

Once we have established the spring rates we recommend a strut and shock package for the car that reflects the correct dampening properties needed. We also take into consideration the fact that different types of struts and shocks are going to provide variable rates of deflection under stress and so the overall driving goals for the vehicle being modified are used to help make this choice.

Our recommendation of self-adjusting or adjustable shocks and struts is dependent upon the driving goals and the driver’s needs for real time control of adjustability. As an example, for drag racing applications we would recommend adjustable struts and shocks so that the dampening properties can be adjusted separately for street and track use. For road course/auto cross use we recommend both self-adjusting and adjustable units depending upon the actual needs of the driver. Due to the fact that there are some self-adjusting units available today that work well for street and track use this takes away the guess work for the weekend driving enthusiast causing us to recommend them in many instances.

Upgraded bushings are always recommended for the purpose of adding strength and durability to these chassis points. We recommend polyurethane bushings in most locations for use in street/track combinations. These limit deflection while retaining acceptable compliance in the chassis. I will address other bushing choices for more aggressive applications in a later article.

John Brooks

BROOKS Performance

www.brooksperformance.com