Q. How or where do I learn about race frame and roll cage fabrication? Do automotive engineers produce specs and design for a specific vehicle? After fabrication,does a frame and cage require a weld and materials test? I would guess that a professional NASCAR team would require a weld sample and the welder follow plans for the car. But what does the weekend dirt track racer do? (Submitted by: CHARLES from DALLAS TX)

A. Most of these race car engineers design a chassis for specific requirements and styles. Weld testing is done to get the proper strength and flex requirements. Destructive tests are usually done. Specific designs vary. Road course type cars vary from oval type. Different length ovals have different design specs. How the front end geometry works is a major concern when designing a car. How much built-in caster and camber percentages and what type of caster and camber gains or losses will be imposed on the chassis as it goes through the corners. There is a base setup that gets refined during testing at a particular track. NASCAR sets specific guidelines for the main cage structure of all the race cars. They inspect these at the time the car goes through pre-race inspection. Different sanctioning bodies have their own set of rules based on years of experience racing at the tracks they attend. Dirt track racers have to follow some type of rules guideline enacted by the track they run at. Most chassis builders know what they are doing when it comes to weld quality.