First of all, thanks everyone for the very helpful replies! This is the kind of response I was hoping to garner, I know my design needs work.
horizenjob, I can understand your bias towards one type or another, no doubt. I agree that the mid-engine exo style car may be heavier and not quite as strong, but aesthetics are somewhat important to me (count me ashamed, but honest) and I just love the shape of the exo type car. I think with proper design it can be close to as strong, and hopefully as light as a 442.
I have access to Solidworks 2014 at work and at home, as well as AutoCAD 2013 and ProE Mechanica. I'm having a great deal of difficulty getting any useful FEA out of any of these, what do you all use?
In reference to what
horizenjob, Aetro, and
JustDreamin mentioned about node connections and chassis stiffness, that will be my next refinement. It's funny, I thought I did a decent job of sticking with node connections, but when I look at it objectively, I do see many areas in need of improvement. The floor and front firewall area will be my first areas to attack.
In reference to the curved tubes, I agree that it's a weak point in the design, but I found that keeping them straight made making space for occupants very difficult (i'm 6'-4", 210lbs). The tubes are only bent slightly, the center of the long tubes is only 4" off, but I know that is splitting hairs. I'm definitely going to be rethinking my chassis and trying for more triangulation to increase strength and rigidity.
JustDreamin, when you are refering to halo bars, are you suggesting that I put one over each occupant within the main roll hoop? Safety is my primary concern for this car, since it will indeed be seeing track and autocross use on a pretty regular basis.
I have removed the curved overhead tubes in favor of a crossbracing design over the cockpit, as well as shortened the rear overhang. Thoughts?
Attachment:
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Attachment:
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(pay no mind to the front suspension pickups, they are a very early draft right now.)
Last question for today: the material I've chosen for the main roll structure is 4130 1.5"x.063" tube. On my first pass through the SCCA rulebook, this seemed to surpass the requirements for cars 1750lbs and under. Should I be using heavier tube, or larger diameter tube? I'm having a difficult time getting a baseline idea for what the typical size is. All other smaller tube is 4130 1.0"x.063 tube, is that overkill?
Thanks in advance for all the assistance and feedback guys, I really appreciate it.