I have probably built a dozen or more boxed frames during my dirt track racing days, and I've come up with some decidedly biased opinions in the process. There's one basic principle when building a dirt car- - - -make it three times as strong as you think it needs to be, and don't be too surprised when it breaks! At the same time, weight is the mortal enemy of the "Go fast- - -turn left" crowd. We built 'em light and strong by cuting a series of football-shaped holes in the boxing sections, and actually had less distortion from crash damage than the ones we left fully boxed. If you use a template and a plasma cutter to make the holes, it looks pretty good, too.
Jerry
