Understanding Handling Characteristics in Relation to Race Suspension Tuning

by: Miroslav Ovcharik

Two general terms are used to describe the handling of a car: understeer and oversteer. Understeer (also known as tight or push) occurs when the front wheels of the car lose traction before the rear wheels in a corner. The car is difficult to turn and “pushes” toward the outside of a turn. Oversteer (also known as loose) is the opposite condition. The rear tires lose traction before the front tires. Hence, the rear of the car is “loose.” It slides toward the outside of the turn, and the car feels like it is going to spin out when it is on the edge of control.

The goal of suspension tuning is to make the car “neutral,” not oversteering or understeering. When the car is neutral, you should be able to control what it does in a turn by using the throttle. Giving a burst of throttle should make the back of the car slide toward the outside of the turn and allow the car to turn better (in effect making it looser). Getting off the throttle should make the back of the car step back in line ("tightening" up the car).

When the car is neutral, it is easier to control, creates less wear on the tires, and usually allows for faster lap times. I say usually because a slightly oversteering car can also yield fast laps. However, this is difficult to achieve because the driver must react instantly to the car sliding by counter-steering. If the reaction is not quick enough, the car will slide sideways achieving a large yaw/slip angle (the angle between the direction the car is pointing and the direction it is actually moving). This will scrub off speed and may even cause you to spin out. Therefore, an oversteering car can be fast but only with a skilled driver.

On the other hand, an understeering car is limited by the grip of its front tires on the racetrack. Even a skilled driver will not be able to clock fast laps with a severely understeering car. Nonetheless, you may want to set up your car for slight understeer to make it more stable and forgiving. With an understeering car, overdriving (getting on the throttle too early in a corner, for instance) will simply make the car slide straight. The condition is easily corrected by getting off the throttle. Overdriving with an oversteering car is much more likely to lead to slower speeds or loss of control.

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About The Author


Miroslav Ovcharik

I have been an automotive enthusiast throughout my life and have participated successfully in various amateur racing series. I specialize in tuning the Nissan S platform cars, particularly the US domestic market Nissan 240SX. Visit my website http://www.240edge.com to get more information about me and 240SX performance modifications.

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