The Ultimate Guide to Suspension and Handling Part X: Bump Steer/Toe Steer
It's time to think about suspension. Some of the most common handling problems that you are the most likely to see on modified street cars and race cars based on production chassis, especially in racing classes that do not allow relocation of suspension pick up points are bump steer and toe steer related handling issues. Bump and toe steer can have significant negative effects on a cars handling which is manifested by steering pull, twitchiness, instability, steering inaccuracy and unpredictability. All of these things are scary for drivers to deal with.
For most production based modified cars, the most common reason why bump and toe steer becomes a problem is due to over lowering the car. Most modern cars have bump or toe steer by design and over lowering the car puts the suspension geometry in a position that increases bump and or toe steer to the point where it becomes a serious handling problem. This is one of the many reasons why we always suggest lowering a car only 1-2 inches at the most.
So now that we've established that bump and toe steer are common and serious issues, how do you avoid and fix them? Read on!
Read the whole series and learn how to make your car handle!
Steering precision and stability are both affected by bump steer. Bump steer is steering input independent of what the driver is doing with the steering wheel created by the suspension moving through its stroke in response to bumps and cornering induced body roll. It is caused by the suspension links moving in different arcs than the steering linkage as the suspension follows its stroke.