[Zeke]

What do you want to do with the car? Autocross or fast street driving (not reccomended)? Tell us more about the car, i.e., tires, wheels and springs and shocks. Temporary tire pressure adjustments can change the way your car corners, but you won't want to leave them that way all the time or you might get bad tire wear patterns. An example: higher press in back and lower in front will lessen understeer (assuming you started with tire manufacturer's reccomended pressures and the tires match the rims in size).