Performance Trends is a software company that has developed someinnovative packages for understanding your car's setup and motorcombinations. Here are the software programs that are most appropriatefor the circle track racer.
Roll Center CalculatorThis is a simple two-dimensional front suspension layout program. Itcalculates roll center position, camber change, and wheel rates fromspring rates for double A-arm or MacPherson strut suspensions. It letsyou move the suspension through dive and roll and watch the roll centermove and the camber change.
Circle Track Analyzer
The Circle Track Analyzer is a complete vehicle and lap-time simulationprogram. It includes the roll center calculator as the front suspensionscreen, and also includes engine power curve, vehicle, rear suspension,and track screens. From this information, it predicts lap times;on-track roll; dive; dynamic corner weights; lateral/longitudinal andvertical g's; engine rpm range; optimum gear ratio; and much more. Ithas several built-in utility screens to calculate spring rate, weightpercentages, and even "virtual scales" to let you know how much to jacka spring to get the desired crossweight.
Suspension Analyzer
This program deals with the suspension only. However, it is a completethree-dimensional program for both front and rear suspensions. It letsyou do steering inputs such as bumpsteer and Ackermann, antidive, casterchange, rear roll steer, pinion angle change, antisquat, front-to-rearroll couple, and more. Other "adjust" and "optimize" options show theeffects of shimming the upper arms or changing ride heights, or findsettings for minimum bump steer, roll center height change, and muchmore.
DataMite Data Logger
This product is an electronics and sensor package that records what ishappening on the track. It can record various engine parameters,accelerations, shock travel, steering travel, wheel rpm, etc. From thisinformation, it can calculate A/F ratio, tire slip, lap times, frictioncircle analysis, general dive and roll of the vehicle,brake/throttle/steering wheel position, and track location. When linkedwith Suspension Analyzer, it can also show exact dive, roll, steer, rollcenter location, camber, caster, Ackermann, squat, and rear roll steerat any location on the track.
Computerized Chassis Setup from Steve Smith Autosports calculates abaseline chassis setup for optimum racing performance. This screen showsa recommended starting setup for a 2,800-pound Sportsman car racing on a1/3-mile slightly banked paved track. Included in the setup are springrates, shocks, weight percentages, and crossweight. Computerized ChassisSetup also contains additional resources to compute many otherfunctions. This function calculates the exact location of the front rollcenter.
Steve Smith AutoSports offers several computer programs that are quiteuseful for all short-track racers. All programs come on CD and arecompatible with all Windows operating systems. Complete operatinginstructions are included with the programs.
Computerized Chassis Setup
This program calculates a baseline chassis setup for optimum racingperformance. It specifies a starting setup for a competitor's particularrace car and track. Weights and measurements from a race car are enteredinto the program, along with information about the type and size of theracetrack, type of tire, track banking, and so on. The program thenspecifies spring rates and shock absorbers for each corner, sway barrate (if the car uses one), corner weights, weight percentages, andcrossweight. Computerized Chassis Setup also contains additionalresources to compute minimum tire stagger, proper final gear ratio,front roll center, roll couple distribution, and front antidive. It alsocontains a program to calculate the spring rate of a coil spring, leafspring, torsion bar (solid or hollow), aftermarket sway bar, and stocksway bar. This program is useful for any racing vehicle running on adirt or paved oval track--Street Stock, Sportsman, Late Model, Modified,Sprint Car, etc.
Race Driving Simulator
The Race Driving Simulator allows the user to explore different racinglines. A standard late apex line, wide in the entrance, allows a driverto get to the throttle sooner and make a late apex while acceleratingout of the turn.Trail braking and following the inside edge of the track. This producesa line that is shorter and may be quicker, with a possibly higher exitspeed. The combinations of driving lines, braking points, and throttleapplication are infinite with Race Driving Simulator. It allows the userto pick the decision points for braking, turn-in, and throttleapplication, then compare various lines to find the fastest combination.
Race Driving Simulator teaches competitors how to develop the optimumracing line for quick lap times. By defining certain parameters, a linearound a corner is generated and split times are read off the screen tocompare different approaches to the corner. Users can learn when to apexearly or late, and when to use a diamond line. They can evaluate thetrade-off between mid-corner speed and getting on the throttle early.The program helps drivers know when to sacrifice speed in order to geton the throttle sooner. Conversely, they can learn when to maximizecorner speed at the expense of early throttle application. The simulatorcan even demonstrate when exit speed is over-rated. Race DrivingSimulator provides a study of how the car's capabilities--power,cornering, and braking--relate to racing line choice. Not only is thisuseful for lowering lap times, but it can also teach users how to altertheir lines to pass an equal car, or how to set up a re-pass maneuver.The combinations of driving lines, braking points, and throttleapplication are infinite with this program. You can define a tracksector, which includes the braking area, the turn (including turn radiusand track width), and the exit. This program allows you to pick thedecision points for braking, turn-in, and throttle application. Comparethe resulting lines for time and speed, with a plot of speed andg-forces for any point in the turn. The Race Driving Simulator is ateaching tool for the serious racer, not a hand-eye coordination game.The program includes substantial built-in help pages. Race DrivingSimulator applies to all rear-wheel-drive racing vehicles running onpaved tracks.
TirePro Computer Program
TirePro from Steve Smith Autosports quickly and easily performs adetailed analysis of tire temperature data. Individual elements in theAnalysis Results screen in the upper right-hand corner can be selectedfor analysis and chassis tuning suggestions. This screen shows wheelcamber change suggestions. The program analyzes tire pressures and givesspecific suggestions for pressure adjustment. This program also analyzescrossweight and gives specific suggestions for adjusting the chassis.Other screens analyze camber, toe, tire pressure, rear stagger, andoverall vehicle handling, with specific chassis setup changes suggestedin each section.
Most racers are aware of the immense value of taking tire temperaturesto analyze the handling of their race cars. But many don't understandhow to interpret the data that can be derived from tire temperatures.Tire temperatures are one of the most crucial diagnostic tools availableto race teams at all levels.
The TirePro program quickly and easilyperforms a detailed analysis of the temperature data, providinginformation on tire pressure, wheel camber, handling balance,crossweight, weight distribution, and stagger. The built-in analysisidentifies chassis problems, then suggests specific chassis changes toimprove handling. In the analysis window, the user can choose fromindividual graphical depictions of toe-in/out, tire pressures, rearstagger, crossweight, and handling.
Each analysis suggests what settingsneed to be adjusted. As the racer goes through the analysis options, therecommendations include the order in which changes should be made. Forexample, the toe-out screen notes that camber should be adjusted priorto setting toe-out. This ordering of procedures is a valuable reminderto experienced racers and an important guide for rookies. (Do all theright things in the wrong order and you'll be chasing the setup formonths.)
The screen for entering the tire temperature data has fields inwhich to identify the car, track, session (heats, qualifying, feature,etc.), and the weather, as well as a "tires" field where the brand,size, or hardness of the tires can be noted. TirePro allows the user toenter many sets of temperatures and save them for future reference oranalysis. You can analyze current readings instantly or browse saveddata sets to find previous situations similar to those you're facing, tosee what did or did not help the car.
A nice feature is a searchablehelp section to make finding answers to questions fast and easy. Thehelp features are accessible from virtually any part of TirePro. TireProis useful for any race car running on a paved oval track, and for carsrunning on hard, dry dirt surfaces when tires build up adequate heat.
Conclusion
There are many computer programs that will enhance yourunderstanding of circle track race cars and provide critical informationabout your car that can help you make key decisions on chassis setup.Contact these companies and visit their Web sites to learn more aboutwhich ones are right for your racing program.
Editor's Note: This article was compiled by Bob Bolles, who foundedChassis R&D Corporation.
*This story originally published in July 2004 issue