Quote:
Originally Posted by sgtlethargic
I'm curious- "structural reinforcement" for what purpose?
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Well remember, I had no idea what they were actually for. So the term "roof rails" in the rulebook implied, I thought, something strong. So in my imagination, I was thinking maybe to keep the roof from buckling or blowing off at high speed, or something like that. Or even to help in the event of a rollover, although now I realize that's pretty stupid, since that's what the roll cage takes care of.
But then when I started seeing them, and seeing they were thin aluminum strips with almost no strength at all, I was really curious. Could they be some kind of fins to help keep the car straight at speed? Surely not.
So finally I asked and was told they were basically aerodynamic "stall fences" when turned sideways to the wind. Without them, the shape of most cars is enough like a fat wing to cause it to lift off the ground at speeds over 200 mph. But those two little strips, 3/4" high, running the length of the roof along each side, are enough to break up the lift that would otherwise form.
I had a similar thing explained to me about my air dam, which went almost all the way to the ground. That helps a lot when going FORWARD, I was told, but I should make provisions for it to break away or otherwise vent the air that would be trapped behind it if I ever spun out and went BACKWARDS at high speed. In that case, the air dam would catch the air and turn my car into a hovercraft!!! - Or worse. As Tom Burkland put it, "You could find yourself taking flight without a landing plan..."
See, I was going around thinking this salt flats racing was the safest thing in the world; nothing to hit. But then it was explained that there
IS something to hit - the ground! When these cars get to extreme speed, the danger is some aero forces lifting them into the air and then they impact the GROUND with lots of force. Guess that's what kills most Bonneville guys - and sometimes fire.....