Mounting OEM seat belt stalk
Discussion
GC8 said:
Difficult to answer with descriptions and photographs. Are you using side mounts? Are you using the originl sliders? How did the seat belt buckle mount on the original seats?
HiIt's a car specific OMP frame with a Sparco seat mounted onto a set of Sparco seat runners. It's a bit of a squeeze and i'm finding it difficult to see a place where to mount them. The original seats had a hole drilled into the frame of the seat itself with the stalk bolted straight in.
yes i'm mad said:
The original seats had a hole drilled into the frame of the seat itself with the stalk bolted straight in.
Eek, really??? I'm not an engineer, but I wouldn't consider doing this - drilling a hole through the frame to mount a seat-belt to, that it was never designed for, sounds like trouble with a capital T!
In an accident, the weight of a body increases many-fold with the decelerating G force. The amount of strain pulled sharply through the seat-belt mounts is monstrous. I would imagine if it was just drilled through the frame that wasn't designed for this, it would at best pull the seat frame away from the floor, twisting and buckling it forwards and upwards massively - with your body moving with it, towards the steering wheel and windscreen, and probably the roof.
Personally, for your safety, I would be looking at some proper custom mounts, to a solid part of the chassis. Either through the floor, or to the B pillar.
I would take it to an engineering shop and show them what you want to do. If it was me, I would ask them to look at removing the seats and carpet, and welding some pretty hefty steel to the top and bottom of the floorpan or B pillar to build some inherent strength and load resistance, then either drilling through this, or welding a hefty custom-made bracket to it.
Know what I mean?
Ray Luxury-Yacht said:
Eek, really??? I'm not an engineer, but I wouldn't consider doing this - drilling a hole through the frame to mount a seat-belt to, that it was never designed for, sounds like trouble with a capital T!
In an accident, the weight of a body increases many-fold with the decelerating G force. The amount of strain pulled sharply through the seat-belt mounts is monstrous. I would imagine if it was just drilled through the frame that wasn't designed for this, it would at best pull the seat frame away from the floor, twisting and buckling it forwards and upwards massively - with your body moving with it, towards the steering wheel and windscreen, and probably the roof.
Personally, for your safety, I would be looking at some proper custom mounts, to a solid part of the chassis. Either through the floor, or to the B pillar.
I would take it to an engineering shop and show them what you want to do. If it was me, I would ask them to look at removing the seats and carpet, and welding some pretty hefty steel to the top and bottom of the floorpan or B pillar to build some inherent strength and load resistance, then either drilling through this, or welding a hefty custom-made bracket to it.
Know what I mean?
these are the original seats
So I should definitely look into custom mounts?
Are you sure you just haven't mounted the seats the wrong way round?(passenger and driver specific seats).
I made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
I made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
LordLamb said:
Are you sure you just haven't mounted the seats the wrong way round?(passenger and driver specific seats).
I made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
Hi - I will check this now. I'm almost certain the seats are the identical on both sides though, and the adjuster is on the outsideI made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
LordLamb said:
Are you sure you just haven't mounted the seats the wrong way round?(passenger and driver specific seats).
I made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
This. Whether or not this will solve the seatbelt issue, it does look like you have drivers-side seat on the passenger-side.I made the same mistake. The adjuster for the back rest was on the outside of my Sparco's whereas your seats look like they adjust on the inside. Also the logo on the front of the seat is normally facing the outside of the car and not next to the centre console.
There looks like a gap on the other side of the seat for a seatbelt.
yes i'm mad said:
Hi there
these are the original seats
So I should definitely look into custom mounts?
Well, like I said, this is all just my opinion on it all - but I would suggest that if the original seats were designed with a mounting in mind, then the frame would also be designed as such, in order to have strength and resistance to bending in the plane and direction of the force being applied to it, in the event of an accident.these are the original seats
So I should definitely look into custom mounts?
To my mind, just drilling a hole into a frame that the designer didn't think would have a mount is asking for trouble.
As I said, cars and belt mounts are designed in a particular way, to resist the forces applied to them properly.
For example, having a quick Google round finds this information:
"For a car crash scenario where a car stops in 1 foot from a speed of 30 mph, what is the force on the driver? Assume a 160 lb (just over 11 stone) driver.
If firmly held in non-stretching seatbelt harness: Stopping distance 1 ft.
Deceleration = 967 ft/s2 = 294 m/s2 = 30 g's"
Which basically means that your own bodyweight flying forwards against the seat belt, momentarily stresses the seat belt and it's mounts with 30 TIMES your bodyweight to arrest. Which means it has to stop nearly 350 stones in force
See what I mean now?
Drilling holes to bolt stuff into on cars is ok with some things, providing it's done properly. But with a safety-critical item that might have to save your life one day, then I would not risk 'just drilling a hole and bolting it in...'
With a spreader behind the nut and washer, then the OMP mount will be perfectly secure.
When Porsche moved from body mounted to seat mounted belt buckles on the 944 they added an extra pair of bolts at the rear (to 6 from 4). Im surprised that your car only has the four mounting bolts, but the drilled sidemount will be at least as strong as that.
With regards to a concencus: therell always be someone gainsaying others on a forum, so that wont happen.
When Porsche moved from body mounted to seat mounted belt buckles on the 944 they added an extra pair of bolts at the rear (to 6 from 4). Im surprised that your car only has the four mounting bolts, but the drilled sidemount will be at least as strong as that.
With regards to a concencus: therell always be someone gainsaying others on a forum, so that wont happen.
Mixed messages are what internet advice is all about, lol! Different comments from different folk - which all gives you lots to think about!
I would summarise from this then - that ultimately, the decision is yours. For a safety-critical item, one thing I wouldn't necessarily do is take advice from the internet! Only let it give me food for thought...
Why don't you speak to some experts, better versed in such things? I would look at showing it to specialists somewhere like a race car / kit car builder workshop.
Or maybe a certified Ministry of Transport testing station that does SVA approval and certification for kit cars and one-offs. They basically check that all safety-critical items and fittings are up to spec, and will provide proper safety and protection in the event of an accident.
Your call!
I would summarise from this then - that ultimately, the decision is yours. For a safety-critical item, one thing I wouldn't necessarily do is take advice from the internet! Only let it give me food for thought...
Why don't you speak to some experts, better versed in such things? I would look at showing it to specialists somewhere like a race car / kit car builder workshop.
Or maybe a certified Ministry of Transport testing station that does SVA approval and certification for kit cars and one-offs. They basically check that all safety-critical items and fittings are up to spec, and will provide proper safety and protection in the event of an accident.
Your call!
Ray Luxury-Yacht said:
Why don't you speak to some experts, better versed in such things? I would look at showing it to specialists somewhere like a race car / kit car builder workshop.
Or maybe a certified Ministry of Transport testing station that does SVA approval and certification for kit cars and one-offs. They basically check that all safety-critical items and fittings are up to spec, and will provide proper safety and protection in the event of an accident.
Your call!
I will do this actually. Or maybe a certified Ministry of Transport testing station that does SVA approval and certification for kit cars and one-offs. They basically check that all safety-critical items and fittings are up to spec, and will provide proper safety and protection in the event of an accident.
Your call!
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