1973 Camaro - Autocross / Street Car project

[byndbad914]

now at least the discussion begins to involve sizing of tubing and orientation of load discussions. It isn't just "square is better than round" sort of thing. Additionally consider weight when you use 2x2 box v. 2" round, etc and the efficiency that comes from actually doing P/A calcs, buckling if that is critical, etc. Like I said, using square tubing isn't bad, but a general statement like square tubing is better than round is a too general IMO and shouldn't be assumed some sort of rule of thumb. Depending on the length of the section then torsional rigidity also comes into play.

If you now consider all your formulas and design by weight and not just size (which should be a primary consideration in any race car even one with a 3100lb weight reqm't) then you won't use 2" square over 2" round.

Now in some instances like framing out a car it can be beneficial to use rectangular tubing, oriented correctly to have a narrow beam fitment where you need to drop seats between beams v. round tube that is fatter than that orientation requires... if I could have gotten rect chromoly in the size I calc'd I wanted in my racecar I would have boxed my cockpit with it but was stuck using round (I used Finite Element Analysis software to lay out all of my stuff to compare stresses, torsional rigidity, etc in design before I had my chassis built).

Back on topic, again diggin' the car so keep the pix coming!