I am currently debating two frame options for a car project that I will soon be entering the design phase on. I am not sure which frame to go with, I would like to hear some outside input. Note that this will be a small open-wheel track car, rwd with a Subaru flat-4(~125 hp). Target weight with driver is <800 lb.
Frame 1: A triangulated box-style frame, all square tubing cut and welded except the roll hoops directly around the driver, which will be bent round tube. See here
for a general idea.
Frame 2: Similar to above, only using round tubing bent hoops welded to a square tubing base instead of cut and welded square tubing. Engine compartment would still be square tubing.
It isn't so much a matter of performance as safety. My main mental battle is that, while the round tubing hoops will do better in a roll-over, they wouldn't do quite as well to keep their shape in a normal sliding collision. I am mostly aiming for a design concept similar to what F1 uses, where the driver is in a "survival cell" that will not crush or break in any collision(Just ask Robert Kubica
how well it works) and using the rest of the frame as collapsible energy absorbers. Well, let me hear any ideas, I can use as many as I can get going into design.