Search Results

Enthusiasts, accident reconstructionists and racing personnel have always been interested in wheel torque and HP values for vehicles. Modifications to the engine and/or driveline cause factory data to be in error, and special racing engines have no such data available in any case. Engine dynamometers provide useful information, but require the engine to be removed from the car before any testing can occur. Of more interest, particularly in competition situations, is the effect of changes at the driving wheels. We focus here on a simple method of deriving rim torque and HP values from accelerometer data. The data can be acquired using nearly any sufficiently accurate accelerometer package, and the calculations involved can be done by hand or with a spreadsheet program. Unknown vehicle characteristics can be extracted from coastdown tests. Use of a chassis dynamometer is not required.

In the scientific design of racing facilities and cars, a strong interplay exists between the aerodynamic characteristics permitted by the vehicle formula and the banking present at each track. We explore this relationship and in particular the sensitivity of various car and track combinations to changes in nominal values for banking and aerodynamic performance. Specific example calculations for NASCAR and IRL/CART vehicles and tracks are given.

Off-road excursions are common in road racing. Current circuit design practice attempts to control off-road vehicle motion and speed with a combination of gravel traps and barriers. Low gravel trap deceleration rates, coupled with wide variation in vehicle attitude during such excursions, produce an unsatisfactory and unacceptable vehicle response. Barriers and walls, while more effective at creating high deceleration rates, can also produce unpredictable response, and often generate vehicle damage and driver injury when contacted, especially in road racing situations. We focus here on car control methods associated more with the vehicle than with the circuit. A new device, the Vehicle Arrester™, has been developed. Calculations and some experimental results indicate that the device could be extremely effective in producing high deceleration rates and a controlled vehicle heading during an excursion.