Safety of seat belts attachment to seats
Moderators: hot66, Miggs, 58A - 71E, impmad2000, drummerboytom, Barry, Helen, Viv_Surby, Derek, KS, abm914, Mike Usiskin
Safety of seat belts attachment to seats
Steve (911MRP) mentioned at the ESR forum a few weeks ago that Porsche did a crash test in circa 1976 and found that the seat runners open and bend in a crash. So, it made me wonder whether the seat belts attached to the seats in longhoods are safe?
See pics:
See pics:
-
- Nurse, I think I need some assistance
- Posts: 10320
- Joined: Wed Mar 31, 2004 1:27 pm
- Location: Cheshire
- Contact:
Re: Safety of seat belts attachment to seats
First rule of early 911 crash performance is try really hard not to hit anything.
These belts should at best be considered as a token effort to stop you sliding off the seat under heavy braking.
I modified my car to fit the inners under the seat rails and welded a plate to the sill for the outer long ends. Still no more than a token effort if you look closely at the shoulder anchorage…
These belts should at best be considered as a token effort to stop you sliding off the seat under heavy braking.
I modified my car to fit the inners under the seat rails and welded a plate to the sill for the outer long ends. Still no more than a token effort if you look closely at the shoulder anchorage…
-
- Nurse, I think I need some assistance
- Posts: 10320
- Joined: Wed Mar 31, 2004 1:27 pm
- Location: Cheshire
- Contact:
Re: Safety of seat belts attachment to seats
The anchorage moved down towards the waist rail on later cars, probably to improve belt comfort but also would reduce bending into the middle of that skinny pillar.
Not sure about the structure on those later cars, but there not much of it on our early cars, most of the thickness is the trim
This is the later centre mount for the belt to the tunnel. This goes inside tunnel and the anchorage’s pole through slots.
Not sure about the structure on those later cars, but there not much of it on our early cars, most of the thickness is the trim
This is the later centre mount for the belt to the tunnel. This goes inside tunnel and the anchorage’s pole through slots.
Re: Safety of seat belts attachment to seats
I never noticed the lower shoulder anchorage in later cars. Thanks. What year did Porsche make that change? Less leverage on the upper pillar therefore stronger.
I think I will replace my early pillar with the later one.
Will updated seat belt mounting points mean a Q-plate?
I think I will replace my early pillar with the later one.
Will updated seat belt mounting points mean a Q-plate?
Re: Safety of seat belts attachment to seats
This is another reason why Targa's are better than coop's
I cannot comment on the tests, and they might be true. However, the seat anchors/brackets look extremely robust to me, as are the seat buckles which attach to them, I think. I don't see any weak points there. The upper anchors don't look very robust on my Targa pillar either - I would say that is the weak point if anything. A hefty gentleman might cause it to give a little in an accident..
I cannot comment on the tests, and they might be true. However, the seat anchors/brackets look extremely robust to me, as are the seat buckles which attach to them, I think. I don't see any weak points there. The upper anchors don't look very robust on my Targa pillar either - I would say that is the weak point if anything. A hefty gentleman might cause it to give a little in an accident..
Dean
1973T Targa MFI 334 met blu- under restoration https://www.ddk-online.com/phpBB2/viewt ... 28&t=67060
1980 924 Turbo, blu/grn tartan - restored
1973T Targa MFI 334 met blu- under restoration https://www.ddk-online.com/phpBB2/viewt ... 28&t=67060
1980 924 Turbo, blu/grn tartan - restored
-
- Nurse, I think I need some assistance
- Posts: 10320
- Joined: Wed Mar 31, 2004 1:27 pm
- Location: Cheshire
- Contact:
Re: Safety of seat belts attachment to seats
I wouldn’t bother, marginal gains for a whole load of work and potential misalignment.IanM wrote:I never noticed the lower shoulder anchorage in later cars. Thanks. What year did Porsche make that change? Less leverage on the upper pillar therefore stronger.
I think I will replace my early pillar with the later one.
Will updated seat belt mounting points mean a Q-plate?
If you are getting to the loads to make that pillar fold then you’ve probably got a fuel tank on your lap so have bigger things to worry about
Re: Safety of seat belts attachment to seats
.
I'm sometimes of the opinion that 1974 is the best year ever for an air-cooled 911.
Much safer seat belt anchorages
Belt reel recessed into the panel out of the way (and hidden)
Stronger upper B-pillar
Far better seat runner supports pictured below:
Still without a 5-blade fan or thermal reactors (introduced in '75)
Same dash-top as pre'73
Easy to backdate front end using a SWB front bumper and single battery setup
.
I'm sometimes of the opinion that 1974 is the best year ever for an air-cooled 911.
Much safer seat belt anchorages
Belt reel recessed into the panel out of the way (and hidden)
Stronger upper B-pillar
Far better seat runner supports pictured below:
Still without a 5-blade fan or thermal reactors (introduced in '75)
Same dash-top as pre'73
Easy to backdate front end using a SWB front bumper and single battery setup
.
Last edited by IanM on Mon May 15, 2023 1:23 am, edited 1 time in total.
- AndrewSlater
- I luv DDK!
- Posts: 969
- Joined: Wed Nov 30, 2011 3:35 pm
Re: Safety of seat belts attachment to seats
I totally agree - early 74 cars are great!!
PS I did take a double take when I saw the photo
1966 Porsche 912 Slate Grey, red interior - first owner owned for 41 years
1974 Porsche 911 2.7 (The Manhattan project) viewtopic.php?f=28&t=51455
1973 VW 914 1.7 Olympic Blue - ( gone to a good home )
1974 Porsche 911 2.7 (The Manhattan project) viewtopic.php?f=28&t=51455
1973 VW 914 1.7 Olympic Blue - ( gone to a good home )
-
- Nurse, I think I need some assistance
- Posts: 19003
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Safety of seat belts attachment to seats
Interesting thread.
I have personally 'crash-tested' the road seat belts on my '73T Coupe at 40 mph into a tree re-enforced bank at a hillclimb competition run. The shell was 1" shorter on the impact side than the other...and needed a good pull on a Cellette to get it straight.
However, the home fitted inertia Britax seat belts used (from an MGB GT) stood it all well (I'm about 12 stone) but my head/helmet hit the top of the screen.
The car has the road belts on the tunnel drilled through for the bolts with 3mm thick 'penny' washers under the tunnel pressing and to home made brackets to the base of the B pillar and the seat runner pressing (the static one bolted to the shell).
After that crunch, I installed a full roll cage, racing seat and 4 point harnesses with eye bolts connections.
Kept the road belt for comfort on the road.
Top mounting on the B pillar held fast. Just my experiences.
I have personally 'crash-tested' the road seat belts on my '73T Coupe at 40 mph into a tree re-enforced bank at a hillclimb competition run. The shell was 1" shorter on the impact side than the other...and needed a good pull on a Cellette to get it straight.
However, the home fitted inertia Britax seat belts used (from an MGB GT) stood it all well (I'm about 12 stone) but my head/helmet hit the top of the screen.
The car has the road belts on the tunnel drilled through for the bolts with 3mm thick 'penny' washers under the tunnel pressing and to home made brackets to the base of the B pillar and the seat runner pressing (the static one bolted to the shell).
After that crunch, I installed a full roll cage, racing seat and 4 point harnesses with eye bolts connections.
Kept the road belt for comfort on the road.
Top mounting on the B pillar held fast. Just my experiences.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Re: Safety of seat belts attachment to seats
OH, it's your photo? Sorry. I borrowed it from the restoration thread.
Re: Safety of seat belts attachment to seats
Any pics?911hillclimber wrote: ↑Sun May 14, 2023 5:12 pmThe car has the road belts on the tunnel drilled through for the bolts with 3mm thick 'penny' washers under the tunnel pressing and to home made brackets to the base of the B pillar and the seat runner pressing (the static one bolted to the shell).
-
- Nurse, I think I need some assistance
- Posts: 19003
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Safety of seat belts attachment to seats
I'll take few tomorrow and post here.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
-
- Nurse, I think I need some assistance
- Posts: 19003
- Joined: Mon Mar 10, 2008 6:26 pm
- Location: West Midlands
Re: Safety of seat belts attachment to seats
Sorry for the delay, got ambushed into doing some gardening...
Here are a few shots of my 911 installation. Seats are non standard, and the car used to be a hillclimb car.
Simple 30 x 30 x 3mm angle bottom seat anchor brackets bolted to the seat runner. I used the standard belt fixing hardware to ensure all moves freely, driver's side shown:
The MGB GT (but i think a universal fit) reel was attached at the base of the B pillar:
Finally, the attachment to the 'transmission' tunnel. The one strap uses an eye bolt to allow the racing seat belts to be attached. The bolts pass through to the 5mm thick mounting plates underneath.
Hope this helps!
Graham.
Here are a few shots of my 911 installation. Seats are non standard, and the car used to be a hillclimb car.
Simple 30 x 30 x 3mm angle bottom seat anchor brackets bolted to the seat runner. I used the standard belt fixing hardware to ensure all moves freely, driver's side shown:
The MGB GT (but i think a universal fit) reel was attached at the base of the B pillar:
Finally, the attachment to the 'transmission' tunnel. The one strap uses an eye bolt to allow the racing seat belts to be attached. The bolts pass through to the 5mm thick mounting plates underneath.
Hope this helps!
Graham.
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Re: Safety of seat belts attachment to seats
Many thanks for the pictures.
It's interesting that you have the buckles (receivers) bolted directly to the top of the tunnel without a bracket. Will an MOT test pass that?
It's interesting that you have the buckles (receivers) bolted directly to the top of the tunnel without a bracket. Will an MOT test pass that?
Ouch!