I know, this topic is a source of endless noob questions. Here comes another:
So my current situation is stock belts, no roll-bar/cage at all, and a set of reclinable pseudo-racing seats with a composite shell. The car is still used at least partially on the street, and will be for a while (even if I pick up another DD soon, I won't likely be picking up a truck and trailer, so still a lot of highway miles to tracks, etc).
I'm aware that all things considered, there's actually only a very narrow set of safe upgrades you can do that are anywhere in-between "fully stock" and "fully caged race car" when it comes to cage/bar/seats/harness stuff, which cuts out a lot of options right off the bat.
Over the past week or two I had pretty much settled on my next upgrade being a a custom-welded 4-point cage in the rear (high/back enough that my head can't smack it, and of the right dimensions that I could add a forward portion later and meet current SCCA/NASA rules), combined with Scroth 4-point harnesses with their ASM system to prevent submarining (since my reclinables don't have seat floor holes for 5/6/7-point anti-sub straps). This is of course leaving the front airbags working, and leaving the stock belts in for street use.
This seems like it avoids all the big obvious street+track config safety problems. It would be more-ideal if my seats had anti-sub holes and I could install a 6-point, but I think the Scroth ASM thing seems like a pretty decent solution to that problem for now.
I've seen some references to the idea of using a 6-point harness without seat-floor holes (and without the stupid move of going over the front of the seat), by basically routing them under your *** and out the same exit as the lap belts, apparently used in some formula cars. The concept and mounting angles and effectiveness of that setup are a little unclear to me though.
My bigger concern is this: is it safe to put a 4-point cage behind a reclinable, composite seat? It seems like even good-quality ones are subject to hinge failure in serious accidents (esp if rear-ended). If it lays over into the floor in the rear that's a relatively livable outcome. But with the cage bars immediately behind it (and we are talking like 6-8 inches tops), would it smack into them with enough force to crack the composite shell, and subsequently my spine?
I should add: it's pretty much a given that if I upgrade to a full cage down the road, I'd also swap in solid aluminum seats with a bolted or welded seat-back brace to the cage, but I don't think such seats are appropriate at this stage
