[chicane]

SCTA-BNI 3.B.1 states:
The minimum requirements are 1-3/4" OD with a minimum 0.120" wall thickness for CRS... for roll bars.

For roll cages... the minimum requirements are 1-5/8" OD with a minimum of 0.120" wall thickness for CRS OR a minimum of 0.095" for E4130 chromoly... and depending on class... it may be legal to use 1-1/2" OD x 0.095" nominal wall thickness CRS.

But... any class that is capable of 175mph or higher must use the larger tube minimum requirements.

They too recommend the use of low carbon (mild) steel tubing. The pads should be of the same material, 1/4" thick top and bottom plate. For chassis weights under 2500lbs, the must have a parimeter of at least 18" inches (i.e., 4x5") and chassis over 2500lbs shall have at least 22" perimeter (i.e., 5x6").

You'll need someone with an updated SCCA rule book to look up Appendix "C" for the updated rules for the minimum requirements. I do know that ERW is no longer allowed in SCCA for "new" builds... and E4130 is now the main stay.

BTW... $500.00 is cheap. What is your life worth ?? Tight ass or not... saftey and its associated costs are a bargan to the alternative.

I am doing 1-3/4" x 0.120" DOM mains with 1-5/8" and 1-1/2" x 0.095" DOM supports... if the rules dont change. They wont... but I need to spec this to cover multiple sanctioning bodies.