Rollbar / seats / harness stuff, yet again...

ryan0

If thats the case... no one makes a harness bar for these things?

and if you are planning on finding a mounting point for your eventual hoop, why not just have it made half height for now to strap harnesses to?

wstar

Most of the stock parts are designed to give. Even the "hard" bits on them. They'd really hurt to smash your head on, but they *will* give a little. That rollbar won't give, ever. Top windshield frame is kind of out of the picture though, unless you have no seatbelts and no airbags.

Being strapped into a harness without a rollbar over your head is definitely-bad. You roll over and you're basically dead.

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ryan0

a B pillar will not give... it is designed as a 'roll bar'. you think a b-pillar will give if your head hits it, but won't give if the car actually rolls over? (its designed purpose)

and as far as the windshield frame goes (see above)... but also you'd be surprised how much stretching and movement goes on in a crash.


agreed that being strapped in w/o roll over protection CAN be bad. thats why i was asking how they hold up in a roll over. if they hold up pretty well, then i'd rather gamble that my odds of hitting something sideways, or head on, were much greater than being involved in a roll over.

tracking cars safely usually comes down to playing odds...

chances are you are going to hit something at an angle... rollovers are a long shot compared to impact.

in this case he is saying he is going to track the car anyway, and only place a little emphasis on safety for now... fine... his call.

factor in the odds of an 'earnhardt' vs a roll over... how well the OEM roof holds up... the fact that he is going to run 4-pts (available submarine room)... and a reclinable seat (available collapse room).

my money is on harness bar and HANS...

wstar

I don't think the stock B-pillars are design to hold up the car like a rollbar. They might help a little, but they're gonna collapse. I also don't see hitting the B-pillar with your head as being a very likely scenario (at least, not as probably as hitting a rollbar).

If the car distorts enough to bring the windshield frame into my head, I don't think it's gonna be very solid anymore. If I distort enough to reach the windshield frame with airbags and belts/harnesses worn, I don't think it matters what else happens to me at that point heh.


This confused me for a second with the pronouns. I was the OP and the person you're replying to . It's not that I'm only placing a little emphasis on safety. I'm putting a lot of emphasis on safety in general. I think the part you're mis-interpreting there is: the desire for the rollbar wasn't driven by safety concerns, and I don't want to compromise existing safety just to feel more connected to the car in a harness.

The complete OEM system of seats, belts, bags, body is well-engineered and crash-tested. It's not as safe as being in a caged race car, with harnesses, helmet, and HANS, but the big non-obvious point is that most halfway solutions which aren't completely stock or completely race are actually worse than either of them. Everything is intertwined in the safety systems and it's hard to touch just one aspect of it without screwing up the rest.

The stock roof won't probably hold for jack. In a hard rollover this car's gonna be pancaked to the top edge of the doors like a barless convertible, IMHO. It's be nice if that weren't true, and it might not be true, but I haven't seen any evidence of that (including having stripped out my upper interior and looked at it myself).

The 4-point harnesses I was considering are the Scroth ASM ones: they have a mechanism (like many OEM belts) where an extra loop of harness on one shoulder is folded over on itself and lightly stitched. In a wreck, the light stitching rips out and one shoulder comes forward more than the other, putting a slight twist in the body that greatly reduces the odds of submarining, much like an OEM 3-point does.

The reclineable seat definitely can collapse, agreed; that concern was really the point of starting this thread.

My money is on this getting you killed in a rollover.

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ryan0

What do you think they are designed for? They are the 'roll bar' for a car with out a roll bar.





oops... short attention span... my bad.


Not always true.







I'm sorry... i don't get the point.. to just plant you in the seat better?


I'll take those odds any day.


Google images for 'nissan Z crash'... would you have rather been wearing a good harness and HANS, or only the OEM stuff because you didn't have a roll bar?

wstar

They may help, but think about it: there's a reason race cars built on cars with B-pillars still get roll-bars. The B-pillar's aren't perfect, even in your own second pic, you can see where the pillar went over sideways and let the roof come in partially.

re: the windshield frame:

Your pic about this doesn't show a head anywhere near the frame of the windshield. The head has arced down to where the steering wheel / dashboard is. I think hitting your head on the windshield frame itself would suck, but again I still have airbags, and I don't think the arc of my body straining against any belt system will let me head go simultaneously that far high and forward.


Man, this forum sucks at lengthy nested quoting I guess. The point of wanting harnesses at this stage was yes, to plant me in the seat better so my chest isn't moving forward so much on braking, or sliding around on corners. My *** is planted reasonably-well by the aftermarket seat bolsters, but that doesn't do much up top. It's just a night and day difference how connected I feel in the passenger seat of a harnessed car versus the driver's seat of mine.

Well, ideally I'd like the whole world to sense my impending crash and instantly transmute itself to NERF material

I agree that in a non-rollover track accident, I'd be better off with a harness bar, harness, helmet, and HANS than I would be with stock belts and just a helmet. And if I avoid the harnesses on the street (which I would), there'd be no compromise there as well.

However, in the current mostly-stock configuration a track rollover would be pretty survivable all things considered, because the stock system lets my body cave inwards and avoid being destroyed by the roof (3-point belt config, and might still be in the hospital of course). I think with the harness bar instead of a rollover bar, and me strapped in with harnesses, a track rollover would result in my neck easily getting locked into taking way more force than it should, causing a high risk of paralysis or death.

So in order to avoid that fate, I had decided on a 4-point cage to use the harnesses with, thus track rollovers while harnessed aren't so fatal. But then that raises the issue others brought up on the first page: me bashing an un-helmeted head into the nearby rollbar in a street accident.

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ryan0

We aren't talking perfect. we are talking compromise.

you do realize that is more of a sedan.. i can almost press my forehead on my Z windshield frame even while 50 Gs aren't pulling my head forward.



this is where people get in to trouble putting speed before safety... yeah it sucks to slide around in the seat... i have put many a pressure dent in speaker grills from my knees crushing them to brace myself.. but i figure that maybe its the car gods way of telling us thats about as fast as you should go with out a cage.




So what you are saying is that in the case of (probably) 99% of all track incidents, you would be better off with a harness and HANS than you would be with stock belts... but in order to prepare for the 1% (and even smaller fraction of that where severe neck injury occurs) you would rather use a seat belt solution that allows your body to flop around in the car bouncing off anything hard, so that your head is free to not be crushed by the roof in case (again an even smaller fraction) it completely pancakes.

sig11

This is pretty much exactly what I've decided to do. I like driving the Z on the street too much to give it up right now.

CG-Locks are AWESOME. Really helps with the left leg fatigue. I've used them since about half way through my first season doing HPDEs.



Glad to read this thread. It sort-of backs up the decisions I made this winter about my car and streetability. I AM still going to toss in race seats and 6pt harnesses with a harness bar though. I figure it's an acceptable risk in my calculations. I actually just sent an email to a local shop I trust to do the install since I don't know that I will have time before my first event.