Seat Belts / Harnesses What do You Use?

Ian Anderson · 05-18-06, 01:16 PM

I am about to purchase belts for my car

Mainly road use but perhaps track days if it is quiet enough to get past the "namby pamby tree hugging do gooders"

The DAX came with fittings for a retracting lap and diagonal (normal car) front seat belt

I have had a single mounting nut welded on behind each seat for non retractable harness - expecting to use a 3 point system (One behind the neck and 2 existing brackets near the seat).

I have been looking for a suitable harness and they (the 3 point) all seem to come with a long tail (would pick up a mounting point on the rear seat of a Subaru or similar) this attaches to the 2 over shoulder bits and the rest makes sense.

But how do I get rid of all the spare belt and will there be enough space between the bulkhead and my neck for the mounting bracket and 2 shortening bits? My height puts the seat back against the bulkhead.

If this excess webbing can be taken up and these used will they rub the hell out of my neck?

Or do I get a 4 point set and attach both shoulder points to the same mounting nut? - Again has anyone done this and was there a chaffing issue?

Presumably someone has done this before and can suggest the best way forward or even suggest belt / harness suppliers that would work

thanks
Ian

Tony Hunt · 05-18-06, 01:31 PM

Ian,
You really need a minimum of 5 points, including a crutch strap to stop submarining under heavy braking (or worse). The more your driving position reclines, the worse the tendency to submarine.
Also, your passenger would experience the same problem, particularly if there isn't much room in the footwell.
What is liable to happen if you submarine in a lap and diagonal system?

91740Gt · 05-18-06, 02:21 PM

Ian,

Doubtless there will be many points of view regarding belts but you must be carefull in your choice or it could become costly in more ways than one.

If your car is going to be SVA You must make certain that any belt you purchase is fully Emarked and type approved for highway use.

Many full harness setups will only carry FIA or MSA approval labels for racing and will not be acceptable for the test, or even sharp eyed MOT testers who should check the belts annually.

Providing you only do the occasional track day, then your standard two inch harness is acceptable, but it will NOT pass scrutineering as from January this year, if you intend to actually race the car. All harnesses have to be of the wider three inch type and in date with labelling.

Now when it comes to fixing points i seriously suggest you have two shoulder strap loops very strongly fixed to your rear bulkhead. A ...for maximum straight forward strength and B... for comfort.

Submarining is a potential problem especially in competition circumstances.
It can be a pain, in more ways than one, for road use, but for the little extra that it would cost to install, it would at least give you the choice. After my huge head on shunt at Oulton Park last year my crutch may have ached a little, but at least i stayed in the seat, rather than going down under the dash !!!!!!! If you ever do any competition or track days, ALWAYS strap your self in tight, then breath in, and get someone to tighten them again. You will be amazed at how much movement there is when throwing a car around on the track.

Having the flashiest, or most expensive belts will mean nothing if you have a "biggie", and you have not fitted them in the correct way or at the right angles.

Hope this is of some guidance for you.

What happened regarding the windscreen fiasco ?

Graham @ GTA /Gulf Oil UK Racing.

Ian Anderson · 05-18-06, 03:49 PM

Graham
Firstly many thanks for your insights into the seat belt question - yes I am sure it will prompt responses and I'm also sure people will put thought into their answers - hopefully someone with a "not to good system" will also read it and change as necessary and avoid injury.

I think that I will probably go the full 4 point with optional crotch for track days but I am looking for ideas as this will entail extra welding etc. Thanks for your input as I was thinking on 2 inch and will now go for the 3 inch ones. - Do you have problems with neck chaffing etc. Also what distance between the shoulder mounting points would you suggest?

I raced a formula V in Zimbabwe for a year and flipped it at about 90mph when my suspension broke around the fastest corner on the track. I would not be here if I had not had the belts pulled so tight they hurt before the flag dropped. I still managed to pop 24 rivets holding the Ali skin in place on the spaceframe, with my left shoulder so know about movement when you should not.

On the windscreen I'm still looking - RAC were supposedly able to get a Tornado one for a supply and fit but are hopeless on responding. Probably end up sourcing one myself.

thanks again
Ian

Graham Inchley · 05-22-06, 09:32 AM

Ian,

From my experiences in aircraft accident investigation in the RN I became VERY aware of the differences in seatbelt configurations and how it influences the extent of damage to the frail human machine! The most notable incident I investigated involved a helicopter that crashed in Antarctica. Gloves, thick, very, used I can tell you. There were five men onboard, thank God they all survived the accident which was nothing short of a miracle in itself. Two were on despatcher harnesses and were flung out of the main fuselage as it tumbled across the ice shelf at a great rate of knots (110) being pulled along the ice as it went! The two who were in the rear most cabin seats were using the same type of harness, one slack and the other tightened properly. The chap in the slack set-up sustained very serious internal injuries because he "submarined" whilst the other, apart from psychological snags and bruising, walked away! The main rotor blades totally destroyed the cockpit but the pilot survived with broken limbs only!! WHY? Because a spare strap in the cabin area had been attached to the back of his seat arresting it's forward motion!!!!! Middle name "Lucky".
The man who submarined under his lap strap went back the following year and flew over the same area again, well and truly strapped in!
OK, the dynamics of crashing with a GT40 strapped to ones backside and a helicopter (angry palm tree) are different but not that different that the laws of physics would ignore us - unfortunately.
Get the best and pull it tight.

Ross Nicol · 05-22-06, 10:32 AM

I did a scruitineering course not long ago and the advice given was for belts not to be pulled too tight with respect to older human fames. Explanation was that young guys are more flexible than us older (mature) drivers and very tight belts can cause more broken bones in an accident.I have had broken ribs from a track accident, not caused by belts but by the tubes in the seat. I have a fibreglass seat now in the 40 and in the laid back position my backside is in quite a bucket shape, not requiring a crutch strap and no chance of submarining. I used Sabelt 3" up till last year when dates ran out but now have Klippan 3".

Ross

Ian Anderson · 05-22-06, 11:10 AM

Ross

Can you measure the distance between the mounting points on the firewall / roll cage for the shoulder mount seatbelts?

Do you have a problem with belts chaffing your neck - if not you probably have the distance correct and in my book more comfort means less to worry about - more concentration on the job in hand!

thanks

Ian

Ross Nicol · 05-22-06, 11:34 AM

Ian
I'll measure and post for you tomorrow. I haven't noticed neck chafing in the 40 but the Sabelt 3" belts in the Lotus Europa do, so you are probably right, but I will confirm. Have to get this tired body off to bed.

Ross

grrowlgt · 05-23-06, 01:54 AM

What I used in my previous road/competition car was both a retractable 3 pt lap sash belt and a 6 pt 3" harness.

Reasoning: 3 pt lap sash is legal (where I live) and easy to deal with. You don't want to be putting on a 6 pt harness every time you drive the thing, although of course neither my car nor a GT40 is a daily driver.

As for a 4 pt harness - I had one of those and they are pointless to dangerous, at least for me. As soon as you do up the shoulder straps the lap belt and buckle try to ride up from your hips (where it should be) to your stomach (where it should not be).

A 5 or 6 pt harness with wide 3" webbing is the go and the same dual belt system will be going in my 40.

My two cents worth...

Graham Inchley · 05-23-06, 03:42 AM

I agree, a full harness is a pain for regular road use. Hence, my intentions are to have the options for both 3 and 5 point as it is a quick and easy task to change the belts before a trackday outing etc.

Frank Catt · 05-23-06, 04:02 AM

Graham, I can supply seat belts specifically designed for the gt40, to FIA international specifications, with 3 inch shoulder straps and six point fixings. The most important and difficult to get right are the positioning of the lap strap adjusters, most seem to be inaccessable below the seat, theses are designed to be easily adjusted while seated. I also make the seats ! Call me if you want a set. Frank

Graham Inchley · 05-23-06, 04:23 AM

Totally, the lap straps were a real pain in my old 7. If your system gets around this and is minimal fuss to get going then count me in.
Thanks for picking up on this point, detail like this can make such a big difference to the final product and ultimately the fruits of our labour (not to mention cash!).
PM on it's way Frank.

Ian Anderson · 05-23-06, 05:20 AM

Frank

Do your belts also have the necessary E markings for SVA?

Thanks
Ian

Tony Hunt · 05-23-06, 06:58 AM

Quote:

Originally Posted by IanAnderson

Ross

Can you measure the distance between the mounting points on the firewall / roll cage for the shoulder mount seatbelts?

Ian

Ian,
My shoulder straps are 225mm apart.
Janet and I always do up our 6 point harnesses whenever we use the car - after the struggle of getting in, it's no big deal! Besides, as long as you start with the crutch strap and work your way round, you don't run out of slots to put the ends in!
Once the straps are adjusted for you, it's a very easy procedure, particularly if the shoulder straps are loosened slightly first.
I would never consider driving a car with a GT40 driving position without an anti-submarining strap for the reasons already ennumerated - where would your knees go in an accident?

Graham Inchley · 05-23-06, 08:03 AM

I like the original seats for the 40 but I do find the seat squab to be too flat. I like to feel I am sitting in the seat rather than on the seat. For this reason I intend to either modify existing seats available on the market or manufacture my own as in the past where I made an aluminium tub and filled it with plaster cast. Boy did my rear get warm or what whilst it was setting! Worked well in a Bobsleigh but didn't look too good (didn't matter). I expect Frank has a way and means of sorting out something suitable?

Ross Nicol · 05-25-06, 12:35 AM

Ian
My seatbelt hooks behind me are 170mm apart on the drivers side and 180mm
apart on passenger side.The belts come through the seat cutouts and this ties in nicely with the hooks.Hope this helps.
Ross

91740Gt · 05-25-06, 05:48 AM

Ian,

In my first reply to you i said that there would doubtless be many comments regarding your seat belt query..

Well you,ve had a few helpfull ones i hope, but may i just say this as my final advice. The different spacing of shoulder straps is evedent from the measurements given from other contributors. There is no fixed setting.
You must do your own measurement to suit your shoulder width so that they lie comfortably and in the correct position over your shoulder blades and down to the waist belt.

Sorry Ross, but as for having slacker belts the older you are ................
well that takes the biscuit. Maybe your scrutineer was into pram racing !!

Graham @ GTA.

Graham Inchley · 05-25-06, 10:12 AM

I have given this some thought also. I would like the scrutineer to explain this theory about the more mature physique requiring a looser setbelt. I can understand that a very tight belt would prevent efficient circulation of the red stuff which is another subject in itself. Maybe we should start another thread and consult more expert advise to get a definitive answer on what is a very critical subject?