I would be willing to argue that a roll bar with some good foam padding is no more deadly than something like the hoop on the older Z verts or even your top windshield frame. neither are going to give at all if your un-helmeted head hits them.

How well do the B pillars hold up in a Z rollover?

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?

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.

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...

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.

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.

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


http://image.stockcarracing.com/f/94...crash_test.jpg


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


Not always true.


http://www.350z-tech.com/forums/atta...k-dsc01691.jpg

http://www.autoguide.com/auto-news/w...sonville-4.jpg


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?

http://a57.foxnews.com/video.foxnews..._CRASHTEST.jpg

Good thread, some good info in here. I too am going the route of a harness bar with 5-point harness/racing seats for the track. Several reasons, however the primary two are:

1) I agree that a roll bar is the best solution to help ensure you are not crushed in a rollover while wearing a harness, however I do not believe that the car was built with the concept of your body 'falling' into the middle to protect you from being crushed in a roll. This is what the B Pillars are there for, and while certainly not as effective as a roll bar, I am confident that they will in many cases prevent the roof from crushing in on you.

2) The only time I will be wearing the harness is at the track. I think it can be reasonably said that in any type of a crash where you are wearing a harness, that does not involve a roll (assuming a hans device is used with the harness), you are better protected with the harness than without it, regardless of whether it is fastened to a harness bar or roll bar. Also, based on the tracks/Auto-x places I will be going to, the chances of a roll are slim to none, which means despite that added risk in one, unlikely type of crash, the added safety in all other possible crashes more than makes up for it.

I believe there is a picture/post on here of a member that rolled his 350Z down a hill while wearing a harness, without a roll bar, who stated that wearing the harness likely made a big difference. (In that he was uninjured)

Obviously the decision to use a harness without a roll bar is going to come down to what each person is comfortable with (and regulations of the tracks you are at) but for me, the harness bar is a more than acceptable alternative to a roll bar/full cage.

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.

It definitely is designed around this concept. The 3-point belts do this automatically by design (allow you to fall to the inside). Re: the B-pillar, I'll say what I said 30 seconds ago in the other post: it helps, but it can be pushed over or flattened depending on the accident. And if the B-pillar falls, and you're locked into a harness, your neck is the next thing in line for the car's force.

I'm going to really miss my SRM when I go Spec Z!

use an auto then :p!

That was me. And it sure did. I had seats, harness, and a harness bar that did brace between the stock seatbelt mounts. I rolled four times side over side hitting some big rocks. The first roll was a straight drop of about 30 foot plus. I was very supported within the car. The roof did hit my head but it wasn't bad nor did hurt me. I was just a little shaken up. Mostly nerves. Not to say luck didn't play a part. I see where both of you other guys are coming from.

http://i1109.photobucket.com/albums/...lspohn/005.jpg

http://i1109.photobucket.com/albums/...lspohn/006.jpg

http://i1109.photobucket.com/albums/...lspohn/007.jpg

http://i1109.photobucket.com/albums/...lspohn/009.jpg

damn why did you do a baja race on a street car lol jkkk. Glad u walked on that one!

That's why I quit school. Because the have recess and I don't play.:tup: