Is a 6-point harness with stock seats okay for track use?
#21
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Addressing the no-rollcage issue - see my post above from Schroth's web site (PDF) saying this isn't an issue. I think this is one of those 1% cases that people keep regurgitating on the internet. I could be wrong, but Schroth is the most authoritative answer I have gotten yet.
I want the harness for two reasons, in this order:
1. To hold me in the seat better
2. Safety equal to or greater than stock belts in the COMMON CASE (not the 1% case). Amdahl's law, for the engineers out there. By common case, I mean the common accident case. Of course, the common case is that there is no accident, and this is my first line of protection
1. To hold me in the seat better
2. Safety equal to or greater than stock belts in the COMMON CASE (not the 1% case). Amdahl's law, for the engineers out there. By common case, I mean the common accident case. Of course, the common case is that there is no accident, and this is my first line of protection
#2 ... I've read this reasoning (rationalization?) many times and while I understand it, I completely disagree with it. Here's why:
First of all, any accident where a harness would be safer than a stock three-point belt, would by definition NOT be one of those "common" accidents; it's now (for example) probably a high- to medium-speed frontal impact with something. Your stock belts will work in conjunction with your airbags to save you from even the most severe impacts as it is a SYSTEM designed to do so. When you wear harnesses, you effectively remove the airbag set up from your safety system... so you've compromised your overall safety, even though you've improved your belt set up. Now your body/torso are more confined, but your head and neck are not.
Secondly, something you may not have thought about in terms of a harness bar is the bar's relation to your head/neck if your stock seats were to fail backwards (another very common accident like sliding backwards into something or being hit from behind.) Even if the seat back only moves a few inches until it hits the rear deck, if that bar is located such that your headrest would hit the bar, you're looking at a broken neck at best.
You have to remember, that even though those severe accidents are less than 1% probably, the severity of those accidents trumps their rarity. It only takes one. You also need to keep in mind, that when you start going faster whether by skill or vehicle modifications (tires especially) you increase your chances of getting yourself into one of those 1% situations.
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You have to remember, that even though those severe accidents are less than 1% probably, the severity of those accidents trumps their rarity. It only takes one. You also need to keep in mind, that when you start going faster whether by skill or vehicle modifications (tires especially) you increase your chances of getting yourself into one of those 1% situations.
and we do that for thousands of mile per year with minimum concerns.
if God wants you on his side, he'll find a way.
(I agree, the perfect solution would be a properly built cage, racing seats, 6 point harness, hans, fire extinguishers, fuel cell, full nomex suit, balaclava and so on... but again... hpde isn't racing)
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yes but think also that we usually go on the road for daily commute with basic protection and around you don't have only other cars.. you have semi truck, piece of tires on the road, deers... once I almost hit an axle from a truck.
and we do that for thousands of mile per year with minimum concerns.
and we do that for thousands of mile per year with minimum concerns.
if God wants you on his side, he'll find a way.
(I agree, the perfect solution would be a properly built cage, racing seats, 6 point harness, hans, fire extinguishers, fuel cell, full nomex suit, balaclava and so on... but again... hpde isn't racing)
The main point I'm trying to get at is this: we all have to make a decision at some point... do we continue to push our street cars to and beyond their limits? Do we continue to modify them with go-fast goodies, big brakes, trick suspensions, forced induction, r-compound tires, but then think that a "compromise" in our safety system is good enough?
When most people ask these questions on forums, they aren't looking for real answers, they are looking for someone to back up the decision they've already made. I can't tell if the OP is in this place or not, I can only hope that my arguments (as an event organizer and a 9 year participant... 7 of which were on street tires, stock seats, stock belts, in various cars) will help the OP and anyone else reading make a more informed decision.
Last edited by Stack; 04-25-2009 at 04:20 AM.
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Hey Chris, considering how much track time you get in, what is stopping you from getting a roll bar? They really aren't that intrusive or much more expensive than a harness bar considering the added protection. I would think it's a relatively small investment with a huge upside in safety and added chassis rigidity.
#25
The main point I'm trying to get at is this: we all have to make a decision at some point... do we continue to push our street cars to and beyond their limits? Do we continue to modify them with go-fast goodies, big brakes, trick suspensions, forced induction, r-compound tires, but then think that a "compromise" in our safety system is good enough?
When most people ask these questions on forums, they aren't looking for real answers, they are looking for someone to back up the decision they've already made. I can't tell if the OP is in this place or not, I can only hope that my arguments (as an event organizer and a 9 year participant... 7 of which were on street tires, stock seats, stock belts, in various cars) will help the OP and anyone else reading make a more informed decision.
When most people ask these questions on forums, they aren't looking for real answers, they are looking for someone to back up the decision they've already made. I can't tell if the OP is in this place or not, I can only hope that my arguments (as an event organizer and a 9 year participant... 7 of which were on street tires, stock seats, stock belts, in various cars) will help the OP and anyone else reading make a more informed decision.
Hey Chris, considering how much track time you get in, what is stopping you from getting a roll bar? They really aren't that intrusive or much more expensive than a harness bar considering the added protection. I would think it's a relatively small investment with a huge upside in safety and added chassis rigidity.
http://www.ioportracing.com/Merchant...ory_Code=AP174
Some of them require welding, which I'm not sure about for a few reasons (reversibility and cost I guess).
Things would be a lot simpler, I admit, if I would just commit to making my Z a real race car
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You definitely make some good points. I have been trying to decide whether to get a harness, and what kind, for over a year. I'm still not sure what the right answer is, and until I'm pretty sure, then I'll stick with my stock setup. I do "lock" the stock seatbelt in place by reclining the seat, jerking the belt to lock it, and inclining the seat again, so I'm nice and snug. It's ghetto but it works for now. What got me actively looking again was a very good group buy from SPL parts on Schroth 6-point harnesses. That's why I started this thread, then learned that I should not use a 6-point with stock seats.
If I can get a fairly non-intrusive roll bar that is still safe on the street and doesn't require gutting my interior, I'd definitely consider it. I looked at a few on this page:
http://www.ioportracing.com/Merchant...ory_Code=AP174
Some of them require welding, which I'm not sure about for a few reasons (reversibility and cost I guess).
Things would be a lot simpler, I admit, if I would just commit to making my Z a real race car
If I can get a fairly non-intrusive roll bar that is still safe on the street and doesn't require gutting my interior, I'd definitely consider it. I looked at a few on this page:
http://www.ioportracing.com/Merchant...ory_Code=AP174
Some of them require welding, which I'm not sure about for a few reasons (reversibility and cost I guess).
Things would be a lot simpler, I admit, if I would just commit to making my Z a real race car
What kind of price for those Schroth 6-points? You can get G-Force 6-points pretty-much anytime for around $150. Sparco's aren't too far from that as well (and they are now made by Schroth.) So don't get sucked in to spending more money than you need, even if it's a deal relative to Schroth prices.
As far as the roll bar ... there are a number of threads relating to it and the 350Z... the Kirk bar seems to have the best fitment. You may also be able to find someone local to you to fabricate one that will fit better for about the same money. Keep an eye on the classifieds too, every now and then someone is converting a 350Z back to street prep.
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Some of them require welding, which I'm not sure about for a few reasons (reversibility and cost I guess).
In both cases the area will have to be cleaned up and painted.
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Heck, I have all the old interior out of my car available if you don't want to mess up yours.
I'm glad you brought this subject up though or I would never have known about the 4pt belts with the anti-submarining. Tempted to install these in my z32.
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not sure if this was brought up but, if you drive with an instructor, most hsde schools require the driver to use the same restraint system as the instructor. Therefore if the passanger seat has the oem seatbelts, the driver must also use the oem seatbelts.
#30
I always question the assumption that a bolt-in installation is more reversible then a weld in installation. Remember, a bolt-in roll bar has at least twelve 3/8" holes drilled through the body of the car. Those will have to be filled in via welding and then ground down or plugged and sealed after bar removal. A welded in bar gets cut off and ground down to the mounting plates.
In both cases the area will have to be cleaned up and painted.
In both cases the area will have to be cleaned up and painted.
#31
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I've made sacrifices and compromises to do it (limited seat position, no use of back seat.) I've also made a risk concession in that the bar is probably closer to my head than it should be for street use (although I do have high-density padding, it'll still hurt.) I'm willing to take my chances on public roads at normal speeds... and by "take my chances" I mean:
- Staying alert
- Following all traffic rules (for the most part )
- Elliminating distractions whenever possible (phones, food, etc.)
- Knowing that I NEVER know whats "around the corner" (unlike on a road course)
- Assuming that most drivers around me on the street are GOING to do something stupid and being prepared for it
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M- I installed a Sparco harness bar with Sparco 4-point belts last year and with 50+ track days it's the best mod I've done to my car. Since the stock belts aren't removed there's no downside putting this in, IMO. You'll experience less fatigue with the 4-point compared to hanging on to the single shoulder belt all day and since you're not using energy to brace yourself in corners you'll be surprised by how much better you feel what the car's doing. I didn't want a race seat because my car has the the airbag option and I want to keep those for now. When it's a dedicated track car I'll trade the airbags for the roll cage. For now it's perfect for the street (as always) and much better on the track.
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- The proximity of the harness bar to the seat head rest... both with the seat in the normal position, and also laid all the way back (to simulate what might happen in a rear-end collision w/seat-back failure)
- Main mounting points, and any support/strut points
- Harness lap belt/anti-sub strap mounts
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Stack- Will do. I live in Louisville and the Ky Derby is this weekend (I work at the newspaper), so it may not be until next week. Verbally I can tell you the Sparco bar allows full seatback travel on my '05 350Z and the mounting points are on the B pillar. The 350 doesn't use support struts as you may have seen on cars with a backseat like the Evo. Also, it's a 4-point harness, so no sub belt. But I'll put up photos. And I may have to pm you for guidance on that. I've been defeated in trying to post both an avatar photo and a signature. Hopefully I'm a better driver than a forum user...duh
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[FONT=Arial]Stack- Will do. I live in Louisville and the Ky Derby is this weekend (I work at the newspaper), so it may not be until next week. Verbally I can tell you the Sparco bar allows full seatback travel on my '05 350Z and the mounting points are on the B pillar. The 350 doesn't use support struts as you may have seen on cars with a backseat like the Evo. Also, it's a 4-point harness, so no sub belt. But I'll put up photos. And I may have to pm you for guidance on that. I've been defeated in trying to post both an avatar photo and a signature. Hopefully I'm a better driver than a forum user...duh[/SIZE]
Maybe you can make it to the event I'm hosting at Bluegrass in late July! That is, assuming we can get this harness bar thing resolved
#38
Stacy, here are a few photos of the Sparco harness bar in a 350Z:
https://my350z.com/forum/body-interi...na-nissan.html
from thread https://my350z.com/forum/media-share...ld-thread.html
https://my350z.com/forum/body-interi...na-nissan.html
from thread https://my350z.com/forum/media-share...ld-thread.html
#39
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Right... that's the one I thought it was. And in this one's case, I have no problem with the bar itself... it's more in how and where it's mounted.
I still want to see some shots of the bar with stock seats ... maybe even shots with someone sitting in the car, with helmet on.
The other thing that concerns me about the bar is the lack of support struts. Since it's a bent bar, it is conceivable that the force of an impact could cause enough force to rotate the bar on it's mounting point. That's why I'd like to see how it's mounted as well.
My favorite part of that car's build is the $3000 worth of seats, but no anti-sub straps
I still want to see some shots of the bar with stock seats ... maybe even shots with someone sitting in the car, with helmet on.
The other thing that concerns me about the bar is the lack of support struts. Since it's a bent bar, it is conceivable that the force of an impact could cause enough force to rotate the bar on it's mounting point. That's why I'd like to see how it's mounted as well.
My favorite part of that car's build is the $3000 worth of seats, but no anti-sub straps