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4 point seat belts (arness) anchorages
xico_ze54 - 1/2/07 at 11:31 AM

anyone could help me with this issue? what's the most common distance between the two upper anchorages?
I'm thinking about something between 25 to 28cm. what's the average distance people have used?

thanks in avance
Amadeu

[Edited on 1/2/07 by xico_ze54] Rescued attachment fixacao.jpg
Rescued attachment fixacao.jpg


jamesbond007ltk - 1/2/07 at 01:13 PM

They should match your seats. Do you have harness holes in your seat backs?

Also if you mount them straight on the top rail they may be too low to get through or over your seat backs.


xico_ze54 - 1/2/07 at 01:42 PM

quote:
Originally posted by jamesbond007ltk
They should match your seats. Do you have harness holes in your seat backs?

Also if you mount them straight on the top rail they may be too low to get through or over your seat backs.


the seats are not that type you mencioned. they are normal ones, short in height.
the anchorages will be done in an horizontal tube part of the roll cage, as shown in pic. Rescued attachment cintos-02.jpg
Rescued attachment cintos-02.jpg


Marcus - 1/2/07 at 02:52 PM

If the belts are mounted on the rollbar, I think you'll need it bracing to the rear of the car. I'd also weld the rollbar to the chassis to make it structural. UK SVA may have issues with a bolted, unbraced rollbar with belt mounts.


pewe - 1/2/07 at 04:30 PM

Also bear in mind that for SVA the top mounts must be a min. of 400mm above the seat base reference point. Also I don't think mounting to the top rail itself is sufficient. You may need to consider plating across the rear width and/or putting some towers in to achieve min. height (mine look like the Forth Road bridge but that's just me!). Cheers, Pewe


xico_ze54 - 1/2/07 at 06:55 PM

I intend to make almost like the old one I made, but this time with the extra horizontal bar.
I took a look at a December 2000 copy of the SVA book and they are not so specific concerning these items.
They mencion several times "sufficiently strong", nothing more than that.

But still no respond to that measure I wrote first: what's the typical distance between the two upper anchorages? Rescued attachment cintos0042.jpg
Rescued attachment cintos0042.jpg


Mal - 1/2/07 at 11:54 PM

On my Westfield the distance is 240mm.
HTH.

Mal


Fred W B - 2/2/07 at 05:54 AM

I've seen 120 mm quoted somewhere, and that seemed fine when I tried it in a mockup

Fred


Marcus - 2/2/07 at 09:14 AM

The simplest way to determine centres is to get someone to sit in the car and look where the belts need to go. Make sure they're wide enough apart so as not to strangle the occupant in an accident!


xico_ze54 - 2/2/07 at 10:36 AM

quote:
Originally posted by Fred W B
I've seen 120 mm quoted somewhere, and that seemed fine when I tried it in a mockup

Fred

120mm is very "strangling" for anchorages very near the shoulders. 240mm - Mal's wrote - sounds more like making sense.
the solution Marcus said last post is what I'm thinking since the begining, but want to know valid opinions to make it the better possible.

In concerning to the scheme of the roll-bar, the main tube is attached to the chassis by 4 M10 bolts in each side, this make a strong fixing. The 2 tubes that will connect to the rear rail will be secured by 2 M8 bolts, each. Isn't that enough to be considered "sufficiently strong" by SVA inspectors?

[Edited on 2/2/07 by xico_ze54]


wicket - 2/2/07 at 11:26 AM

Min height as diagram. Each upper anchorage points 140mm min from horizontal centre line of seat, 280mm min. centre to centre Rescued attachment seatbeltfix2.jpg
Rescued attachment seatbeltfix2.jpg


Fred W B - 2/2/07 at 02:20 PM

race belt fitting guide


Marcus - 2/2/07 at 05:28 PM

Excellent link Fred, also answers the one about wrapping the webbing round a horizontal part of a roll cage.
Seems a spacing of 250mm is the way to go.


xico_ze54 - 2/2/07 at 09:07 PM

a good link indeed.

now would you take a look at this sketch and say your opinion if this kind of roll-bar/arness anchorages would pass in a SVA test? Rescued attachment roll-bar.jpg
Rescued attachment roll-bar.jpg