UnderSteer/OverSteer General Information


Oversteer: (Rear breaking traction)


As with understeer, both rigid and soft suspensions can cause oversteer. With “roll oversteer” the car leans heavily, hitting the bump rubbers and causing a skipping action of the rear end, often resulting in an inversion of the car. “Rigid oversteer” is brought about by a tight suspension set-up which does transfer sufficient weight to the wheel doing all the work.

Understeer: (Front breaking traction)
(second pic below)

Understeer can be caused by both too hard or too soft suspension. The hard suspension will have a tendency to “jump” on unsmooth surfaces, thus lessening contact between tires and the road. With soft suspension the tendecy to accentuate centrifugal forces by excessive body roll causes the type of understeer that most of us have experienced at one time or another.

Anti-sway Bars & Shock Absorbers
For street use it is advised to stay soft on spring rates and to use bars and shock absorbers for stiffening suspension.

Spring Rates
Spring rates determine the available amount of bump and rebound movemnet. Higher spring rates limit this movement in much the same way as a stabilizer bar. For street conditions, the ideal spring rates would be where the suspension movement ceases just before the bump rubbers come into action. Astute “car sorters” use stabilizer bars and spring rates in conjunction with one another to achieve the best results. Altering spring rates may also require re-specification of the bump-rebound
qualities of shock absorbers. For example, where stronger springs are required, a shock absorber with stronger rebound and softer bump should be selected.

Adjustments to Increase UnderSteer
Lower Front Tire Pressure
Higher Rear Tire Pressure
Smaller Front Tire Section
Larger Rear Tire Section
More Positive Front Wheel Camber
More Negative Rear Wheel Camber
Stiffer Front Springs
Softer Rear Springs
Thicker (stiffer) Front Sway Bar
Thinner (weaker) Rear Sway Bar
More Forward Weight Distribution

Adjustments to Increase OverSteer
Higher Front Tire Pressure
Lower Rear Tire Pressure
Larger Front Tire Section
Smaller Rear Tire Section
More Negative Front Wheel Camber
More Positive Rear Wheel Camber
Softer Front Springs
Stiffer Rear Springs
Thicker (stiffer) Rear Sway Bar
Thinner (weaker) Front Sway Bar
More Rearward Weight Distribution