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The time is getting closer to sort out buying the seat belts, i had thought the 4 point race harness was the way to go but after a little bit of digging around i have found arguments for and against for general road use with no roll cage fitted. They say that the 4 point harness prevents any side movement if fitted correctly so prevents ducking if the car rolls where as an inertia 3 point belt allows the body to roll and duck but there again there is evidence that in a roll its not uncommon for 15 to 20 G's to be experienced which is impossible to fight against so you would have to go with the roll so the argument of a 3 point inertia being safer is doubtful.
A couple of points that are repeated time and again is the anchor mount points in relation to the occupant, one area that is a no no is the mount for the shoulder straps should never be on the floor, they should be either horizontal to the shoulder or no more than 45 degrees (10 degrees being the optimum) below with a short a distance as possible from the rear of the seat, i have seen mentioned no more that 200mm. Apparently if the belts are mounted on the floor with a frontal collision the force is transmitted down through the shoulder strap and directly down the spine which can result in un repairable spinal damage.
The seat belt mount situation is critical to the well being of anybody in the car. Out of interest what has anybody else fitted to these cars, 3 point inertia or 3-4 point harness.
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Images of correct mount positions.
It would be interesting to hear what others think on this issue and what they have experienced with day to day driving with a race harness fitted.
Today i trial fitted a 4 point harness i have lying around to see how comfortable it is and to be honest they are very restrictive for general moving around in the cockpit when pulled tight, you are basically strapped to the seat and can not even turn your head around to look over your shoulder. They do how ever look the part but i think they may be more of a hassle for the driver and certainly the passenger so i am now thinking of may be a 3 point harness as these i believe have a little more room for movement or even a standard inertia type belt that Mr T has fitted.
Even may be one of these, a 3 point with inertia mechanism. This has the best of both worlds looks a bit like a race harness but with easy of use and comfort.
That's exactly right Paul, I fitted those as the inertia gives the free movement for junctions etc but the classic look, unfortunately haven't used them on the road yet but happy with them so far.
To avoid mounting to the floor I welded in plates on the spyder frame at the backside if the fuel tank, the inertia reel is ample length for this and still has free play as intended
Cheers Pops, i am trying to see where i can mount the inertia reel possibly behind the seats, so it will be handy to know roughly where the rear push button latch will be when seated in the car.
One option is to mount the reel on the floor or very near the floor which will require some sort of support bracket for the belt to pass through directly behind and level with the seat top to prevent crushing of the spine in a collision, the other alternative is to cut a slot level with the seat top in the rear bulkhead and mount the reel behind the bulkhead that is if room is permitting, Mr T has something similar i believe with his standard 3 point inertia seat belt.
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Will eventually exit at bulkhead, at the moment the buckle doesn't exit bulkhead but movement is adequate, may open up slot to allow free passage and further movement for bigger drivers..
I initially tried my all-ways acting three point inertia reel belts here -
But it quickly became obvious that the body wasn't going to fit over them without adding a bulge, so I moved them to the Cobra style centre mount, where they work just fine -
Pops Thanks for the info it will be very helpful in working out what can be done, Cheers.
Mr T I had wondered why you had center mounted the inertia reels so thanks for that info and if i can't get the race style 3 point to fit then i will look at the standard 3 point belts.
The decision for me was very much about using the car on the road, not the race track:
On the track you need to be fixed into the car as solidly as possible, mostly to keep your hands and feet on the controls when you're airborne over crests, and partly to hold you solidly inside the shell if you roll it at 100mph.
In a road car you need to be able to twist round to look over your shoulder when changing lanes on dual carriageways, you need to be able to lean forward to see oncoming traffic at junctions and you are most likely to need restraining in a comparatively low-speed traffic shunt at around 20 to 30mph (other crash speeds are available, subject to driver status, just ask WCA over on the Tribute forum...)
Unlike Phil J, who's a committed track man, I never intended to put my car on a circuit, hence the road belts.
Here's my car in its natural environment. Yep, it's for showing off!
I'd agree with the central location as i ended up fitting my Sammio ones in the same place after a bit of tinkering.
At the time I'd been reading the IVA requirements for fitting seat belts in 7's and I decided on a slightly different solution to Towed's as i came across those weld-on threaded mountings.
Ive gone for a pair of Securon 700 3 point harnesses which hopefully should be here early next week, just have to figure out where to mount etc. Thanks for the advice guys.
After much debate Ive also gone for a quick release steering wheel mount for two reasons one for easy access in and out of the car and secondly a good anti theft deterrent, it was the access issue that made my mind up as there's very little room between the seat and steering wheel what with not getting any younger either. The anodizing company has been on the phone to say the parts are ready so next week i will pop over to collect then start to fit the bright work which i am looking forward to start.
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The original steering wheel boss in the right hand image will have to be cut down and an ally adapter made to suit the old boss and new quick release mount.
I had originally thought the quick release boss would mount directly onto the top of the original boss and the steering wheel on to the quick release boss, but this idea throws the steering wheel too far off the dash so to keep the spline part of the original boss that fits the steering column means cutting the center section out to keep the steering wheel close to the dash as originally intended.
It will simply mean turning an adapter disc to suit both parts and drilling the spline part to bolt to the new adapter plate or at least that's what i intend to do.
1965 Britain requires the fitting of seat belt anchorage points in new cars.
1967 Britain requires belts to be fitted to front seats of new cars. The law was later changed to require post-1965 cars to be fitted with front belts retrospectively.
The seat belts arrived yesterday so today Ive been working out where and how to mount them. There's little room directly behind the seats as the fuel tank is mounted just where the ideal position would be so at the moment Ive gone with mounting the inertia real down near the floor directly behind each seat bringing the belt up and through a bracket ill machine up out of ally this next week, this will bring the belts level with the top of the seats and prevents pressure on the spine in a collision.
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The red line shows the travel of the belt and the green square indicates the bracket position i need to make.
One of the belts bought form Amazon, they sell them as one but the description states a pair so if you argue the toss you end up with two belts for the price of one, don't know how long they will leave the description after admitting the error so will more than likely change the product description very soon.
Parts arrived back from the anodizes but i must say i prefer to see the bare machined ally finish, it just looks better.
Made a little progress this week with the seat belt brackets.
My thought is to bolt through the top box section behind the rear bulk head, welding in crush tubes for the bolts to pass through and bolt to a 10mm spread plate at the rear of the box section, this way i hope to achieve maximum security in the event of a collision. The section where the belt passes through has a 3mm chamfer to prevent any chaffing of the belts when in use.
Bracket loosely in place above the seat, its looks to be the solution but i will know better once the inertia reel is fastened to the lower box section near the floor, need to make sure there's enough belt movement before the back catch meets the ally bracket.
If anybody is waning in their build then watch this http://www.youtube.com/watch?v=G0eIVfr5Dck to get the juices flowing. I've watched it a number of times now and its never boring.
Bought a period dash horn button made from Bakelite as were the originals.
Originally i had made a steering wheel horn button but now that Ive gone down the road with a quick release steering wheel Ive had to redesign the wheel mount and add a dash mount horn button for ease.
Just about finished the re-designed mount so will post pictures this weekend.
Its made of three main parts to adapt the detachable mount to the original steering column.
First an adapter mount was made for the original spline casting, the casting was machined down to size and fixed to the new part with three 6mm high tensile counter sink bolts, basically this made it possible to mount a detachable mount to the original steering column.
New base spline mount with the bottom half of the detachable mount fitted to the steering column, the original hex nut was used to tighten this part to the steering column after the bore of the detachable base mount had been opened up.
Plate made to attach the steering wheel, two different hole pcd's to match the detachable part and the steering wheel. High tensile counter sink bolts used which will be hidden once the wheel is in place.
Steering wheel in place with plain center plate, the horn push was originally here but to make it easier for myself ive now mounted the horn push on the dash. Stainless steel counter sinks hold the steering wheel in place.
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