Oversteer/Understeer Characteristics of a Locked Differential

942485

12/01/1994

Event
Motorsports Engineering Conference & Expostion
Authors Abstract
Content
The type of differential used in a vehicle has an important and often-neglected effect on handling performance. This is particularly important in racing applications, such as in IndyCar racing, in which the type of differential chosen depends on the course being raced (superspeedway ovals, short ovals, temporary street courses and permanent road courses). In the present work, we examine the effect of a locked rear differential on oversteer/understeer behavior. Using a linear tire model, it is shown that employing a locked differential adds a constant understeer offset to the steering wheel angle (SWA) -v- lateral acceleration vehicle signature. A computer simulation of steady-state cornering behavior showed that the actual effect is much more complicated, and is strongly influenced by static weight distribution, front/rear roll couple distribution, available traction and the radius of the turn being negotiated.
Testing performed on a Formula SAE racing car was used to verify the simulation results, and to examine limit-performance differences between theory and experiment.
Meta TagsDetails
DOI
https://doi.org/10.4271/942485
Pages
11
Citation
Hopkins, P., and Metz, L., "Oversteer/Understeer Characteristics of a Locked Differential," SAE Technical Paper 942485, 1994, https://doi.org/10.4271/942485.
Additional Details
Publisher
Published
Dec 1, 1994
Product Code
942485
Content Type
Technical Paper
Language
English