Balance
We're constantly preaching balance to our customers when it comes to installing performing upgrades on their cars. It is our philosophy that a car has three basic objective measures and one subject measure when it comes to performance: positive acceleration, negative acceleration (also known as deceleration or braking), and lateral acceleration (turning, or the ability to change directions). The fourth measure combines the three objective yardsticks into a subjective rating that's all about balance and feel-- how the three acceleration measures combine into a whole experience.
Typically modern cars come from the factory pretty well balanced. By that I mean the engine doesn't overpower the brakes, the wheels are sized for handling on par with the speed capability of the drivetrain, and so on. When you decide to upgrade just one part of the acceleration measures I outlined, you are necessarily going to tax the other two and throw the balance off.
Case in point, we upgraded the suspension on a car earlier this year (KW coil-overs on all four corners, thicker Hotchkis sway bars front and rear, full track alignment). The customer's times at a local road course immediately dropped 5 seconds, but the car lasted about half the day, when his stock brakes gave out. The additional speed the new suspension set-up found overwhelmed the brakes. The same result might have happened if we just upped the power of the engine. Now he needs bigger brakes and stickier tires.
You see the pattern? When you decide to increase the performance of your car, you have to look at the entire system and understand how each part relates to the balance of the entire car. When the car is balanced, the seat of the pants feel is not only better; it inspires confidence when you're pushing the car.