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Harness mounting positions - again..!!
Jumpy Guy - 27/8/03 at 10:05 AM

I know its been done before, but I cant find a definitive answer, and since the SVA book is out of circulation at the moment, its down to you guys...
I intend to mount my four point harnesses, top mounts, on the horizontal chassis rail behind the seats, passing the harness through the harness holes in the seats.
Is this OK? the mounts will be low, but my understanding is that the harness holes in the bucket seats is the relevant point?
any opinions?

Simon - 27/8/03 at 01:59 PM

JG

I emailed Cobra Seats about this very point, and was going to post his reply - but can't find it. Typical.

Anyway, the g(j)ist of it (IIRC) was that that was what most people do (his mate had just passed his SVA with same set up), and FYI it's what I'm doing (me that is, not the chap from Cobra!!).

The SVA Manual (and anybody with a book to hand care to correct me) states that the angle of the harness straps from tube "O" (that's the one to which you refer I believe), though harness holes should not be greater than 45 degrees.

HTH at bit.

ATB

Simon

JoelP - 27/8/03 at 04:56 PM

quote:
Originally posted by Simon
JG

The SVA Manual (and anybody with a book to hand care to correct me) states that the angle of the harness straps from tube "O" (that's the one to which you refer I believe), though harness holes should not be greater than 45 degrees.

Simon


Do you mean not more than 45 degrees down? or left right? I had assumed they had to be more level (ie less than 45) but it would be good to know for sure. This would reduce downward force on the seat in a bump (as you go forward), which sort of makes sense.

Im using a 4 point seat, do the bottom straps just go to the bottom rail behind the seat?

Jumpy Guy - 27/8/03 at 07:21 PM

I had thouht of mounting onto a handy bit of chassis!
Is there a minimum thickness of metal that the bottom harness mounts can be mounted onto?

Rorty - 28/8/03 at 07:05 AM

Harness fixing points are universal now in motorsport internationally.
The shoulder belts should point backwards and downwards at an angle of about 45 degrees after they leave your shoulders. This is imperative, as if the belts continue on an upward path from your shoulders, you stand a very good chance of being injured in a crash.
The lap belts should be anchored behind theseat at floor level. The crotch strap (of 5 or 6 point harnesses) should also be attached behind the point it enters the seat.
I would be very surprised if SVA would differ.

Simon - 28/8/03 at 09:15 AM

JG/Joel,

My lap belts are bolted to triangular shaped 4mm plate fully welded (both sides) to the floor and penultimate rearmost upright chassis tubes. Might be worth also noting that the uprights to which the 4mm plate are welded to are attached to the rear most upright tubes by seam welded sheet. Have a look at:

http://forum.locostbuilders.co.uk/xmb/photos/cgi-bin/showpic.pl?10000059.jpg

and you'll see what I mean.

You should find complete fitting instructions included with your harnesses.

The SVA manual shows (via piccies) the parts on a 7 esque chassis that are acceptable for mounting your harnesses.

As for the shoulder straps, Rorty has explained it better than I.

ATB

Simon

[Edited on 28/8/03 by Simon]

Jumpy Guy - 28/8/03 at 09:37 AM

But I dont have a SVA manual, and cant buy one anywhere! as discussed on previous threads, its out of print at the moment.....
If some kind soul could scan the pictures, that show these mounting points , it'd be much appreciated!?

Rob Lane - 28/8/03 at 03:23 PM

Try http://www.jpmast.nl/svaChapters.htm for your info.

It's the SVA manual online.

Rob Lane

JoelP - 28/8/03 at 04:15 PM

That website says (i think) that the rear top mounting must be more then 50cm above a reference point (your bum), and that all mounting points must be suitably strong, ie braced and triangulated etc.

Is this a good summary or have i missed something?