A few general notes on car setup:

• Tires are your most important upgrade: They are the ones that end up doing all of the acceleration (not the engine), the slowing down (not the brakes), the turning (not the steering), the dampening (not the “shocks”) and sustain a load of physical forces, weight and heat, as well as less-than-perfect surfaces. It’s therefore imperative to maintain tires through careful choice of good tires (also on road cars) replacing them once aged (a three-year old tire conducts badly even if it appears new and has not been driven on) or once they met their mileage. Tires are best replaced in foursomes (good tires don’t go in the back – they go on all four wheels). Tires must be regularly checked for damage or excessive wear, and be properly inflated every second week, and in any long trip/track session. Inflate when cold. Consider load and tire temperature when inflating for a track session/trip.
• Suspension is the second priority. Remember, it’s all about compromising between stability and turn-in obedience, grip versus ride comfort, grip versus tire wear, etc.
• Brakes are also important for the track, but it’s important not to change the brake bias dramatically and to remember that eventually the stopping force is created by the tires. Stronger brakes require grippier tires.
• Engines drink fuel and breath air. They are best upgraded not by how they drink fuel, but by how they breath air. Ensure the coldest air possible flows through the most unobtrusive air filter to give your car the air it needs!

Remember that the largest variant is the driver. Period. A good driver can drive very effective in bad cars. A bad driver can mess up very good and forgiving cars. Blame yourself for handling problems before you blame the car and go to changing it’s setup. When you do make changes, make them small and one step at a time. Make a step, check the outcome, then decide whether to make another change.