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-   -   Single-point harness mounting... (https://www.rx7club.com/race-car-tech-103/single-point-harness-mounting-691699/)

Valkyrie 09-25-07 10:42 PM

Single-point harness mounting...
 
Are there any race-style harnesses that can be safety mounted to one eye loop bolt? I mean, you've got tuner harnesses, but no good camlock harnesses that are designed to be bolted to one point (that I know of).

Or if you MUST use two points, how far apart MUST they be if you're mounting it to two holes reinforced with a metal plate? A single-mount would be great for an FC with full interior... but two points would be harder, since the shock tower takes up a bit of room.

Unless having the holes offset a little bit is OK?

Black91n/a 09-25-07 11:53 PM

Hate to break it to you, but unless you've got a roll bar with harness bar and seats with harness holes you can't safely use harnesses in an FC. Mounting them to the floor will either put them at too great of an angle, causing spine compression in an accident, or if you mount them far enough back to correct this they'll be too long and will stretch too much in a collision, again making it unsafe. The seats are also too wide at the shoulders and will prevent the belts from properly seating on your shoulders and will make it easy for them to slip off in an accident, making it very unsafe.

Valkyrie 09-26-07 12:11 AM

My seat has harness holes... and if you were to mount it into the hatch floor area (as close to the storage boxes as possible, perhaps with a spacer...), it would be within 24 inches or so (not obscenely far), and within an acceptable angle, although the allowable angle seems to vary from maker to maker.

Scroth says that you can use a fairly deep angle (like 35 degrees or so) as long as you have an "approved" fixed-back racing-type seat (which I do, minus the approved part). OTOH, Takata says you can go as far as 45 degrees or so... while so makers so within 5...

IIRC, Scroth doesn't give a specific maximum length, so long as that you cross the shoulder belts if you're mounting them to the floor, and keep them seperated with roll bar padding if you're looping them onto a roll cage.

The issue with rollover protection is basically a minute issue for my purposes (autocrossing and maybe drifting). And actually, I would imagine my seat would actually give *some* protection since it's higher than the stock seat.

Mahjik 09-26-07 09:03 AM


Originally Posted by Valkyrie (Post 7368873)
The issue with rollover protection is basically a minute issue for my purposes (autocrossing and maybe drifting). And actually, I would imagine my seat would actually give *some* protection since it's higher than the stock seat.

Unless the seat is higher than your head, it won't matter as your head will still be the highest point *if* you roll and the roof caves in. That's the problem as a harness will hold you upright were as a standard seat belt will allow you to bend. So if your head is the highest point (i.e. no rollbar), and you are wearing a harness which is holding you upright, you have a possibility of the next thing that gets crushed in a rollover after a roof is your neck/spine.

I'm not saying you should or shouldn't do it, I'm just stating what the issues are and letting you decide what you want to do with your car.

Valkyrie 09-26-07 09:28 AM

Your head is only the highest object until it bends forward... the neck is actually very flexible after all... the real problem comes from when your neck is being twisted in a diagonal direction (like a noose, which is placed to the side and behind your head to break your neck).

And my new seat is very close to being as high as my head (albiet without a helmet).

Gene 09-26-07 10:35 AM

IIRC they used to make Y-harnesses but they are no longer FIA or SFI certifiable.

Black91n/a 09-26-07 11:00 AM

Actually I'd think that drifting could potentially have a really high risk of rollovers depending on where it's being run. If it's at a track then all you need to do is drift off into the runoff area and catch a wheel in the grass or gravel then over you go, violently.

Even an FIA approved seat won't hold the car up in a rollover. It probably wouldn't even hold the car up if you were to gently place it on the seat. Bend the neck forward enough and it'll snap, besides, it won't take much to crush the roof in that much, as that'll only gain you a few inches.

The Autopower roll bar is quite reasonably priced and is a good unit. I'd reccomend it and it'll eliminate the length and angle issues with the harnesses.

To me it's a pretty simple issue, I value my life highly, so I'm willing to spend the $$ to protect it. Better safe than sorry right?

ptrhahn 09-26-07 11:37 AM

Advice: If you've got a race seat, but no roll bar, try using your factory belt with a CG lock (www.cg-lock.com)... I've got a roll bar anyway, but I use it with my Sparco EVO and find that you're held in pretty well, but don't have to deal with harnessess.

I found that I had a tough time finding a good driving position w/ 6 pt's, that they were uncomfortable and restrictive, and a PITA to dick around with before a run. For your purposes and setup, you might find you don't need them.

Valkyrie 09-26-07 11:37 AM

Well, I wouldn't expect it to hold the car up, just to give SOME resistance to the roof, which already roll over protection in the form of a roll hope built into the B pillar (at least that's what I heard)...

Drifting at higher levels obviously requires a roll cage, but I'm talking about amateur/beginner level stuff in parking lots.

I would love to use a CG lock, but I've got mouse belts, and no time to find junk yard parts to do the conversion, nor the money to just buy new ones.

ptrhahn 09-26-07 11:40 AM

I would expect a race seat to provide ZERO effective roll over protection. The roof itself is stronger. Any force sufficient to crush your roof, is gonna do in your seat.

ptrhahn 09-26-07 11:40 AM

Mouse belts?



Originally Posted by Valkyrie (Post 7369870)
I would love to use a CG lock, but I've got mouse belts, and no time to find junk yard parts to do the conversion, nor the money to just buy new ones.


Valkyrie 09-26-07 12:11 PM

A derogatory term for automatic seatbelts... the design means you can't use CG locks. They also provide *no* hold for your lap except your extreme deceleration.

Although the shoulder belt automatically locks in place when you accelerate or decelerate hard, which can give you a little bit of hold (but not as much as a bucket seat would, versus the normal seats).

Auto belts also get in the way when you're trying to use a harness, unlike manual belts, which you can just sort of tuck out of the way.


And I'm not suggesting that a race seat would be a surrogate roll bar/cage, simply that I believe it's possible that the seat could simply keep the roof from not crushing as far as it would have otherwise in a partial roof failure (maybe giving you 3 inches you wouldn't have otherwise, which might be enough to avoid spine or head damage).

ptrhahn 09-26-07 12:25 PM

I know you said you didn't want to, but it might be worth a look at retro-fitting the regular style belts for your purposes and setup.


Originally Posted by Valkyrie (Post 7369968)
A derogatory term for automatic seatbelts... the design means you can't use CG locks. They also provide *no* hold for your lap except your extreme deceleration.

Although the shoulder belt automatically locks in place when you accelerate or decelerate hard, which can give you a little bit of hold (but not as much as a bucket seat would, versus the normal seats).

Auto belts also get in the way when you're trying to use a harness, unlike manual belts, which you can just sort of tuck out of the way.


Don't bet on it.


Originally Posted by Valkyrie (Post 7369968)
And I'm not suggesting that a race seat would be a surrogate roll bar/cage, simply that I believe it's possible that the seat could simply keep the roof from not crushing as far as it would have otherwise in a partial roof failure (maybe giving you 3 inches you wouldn't have otherwise, which might be enough to avoid spine or head damage).


Valkyrie 09-26-07 12:42 PM

I do want to retrofit it, I just don't have 350 dollars to spend on new belts and trim (just for the driver's side), nor do I want to use belts from a junk car that has been sitting open, in the rain for up to a year...

ptrhahn 09-26-07 12:46 PM

Well, a Shroth harness will set you back $300+ for one side, without mounting accessories.... course you can find cheaper brands.


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