Emergency help required fellow PH'ers - bucket seat fitting
Discussion
Help - quick question for you all re bucket seat fitting
Background
I have a 986 Boxster S (2000) and love it to bits. Was thinking of trading in but I realised that the cash to change to would be very silly and quite honestly there's nothing I'd want to change it for in a fast 2 seater convertible kind of way apart from a newer Boxster S and even that would be second hand again. Knowing how I have maintained and looked after the car I therefore decided to throw some extra money at my own car and get a few things done;
1. Clear light upgrade
2. Change stereo to new Becker Cascade (booked into Prestige audio on Friday for this), and
3. Fit a pair of GT2 style buckets (just beacuse I want to and don't find the present seats as supportive and holding as my old Elise ones)
So I did my research and found the Deisgntek carbon fibre ones on design 911, ordered and all has gone smoothly with the order arriving in good condition an dexactly when delivery was promised. Now we come to the problem...
Problem
Upon fitting (by the chaps at GT One during his service) it looks as though the only way of getting the inside seat belt holder (i.e. the plastic clip that the metal tongue goes into) to fit is to bolt it to the outside of the seat using a small 8mm bolt. The original bolts to the runner using an approx 15mm bolt. Not happy with this new solution as am worried about securing my seat belt to such a small bolt. It looks like we can't attach to the original fitting and still be able to slide the seat back and forward (would need to as Mrs CVP is much shorter). No pictues yet as am work well away from the car. I need to retain the inertia reel seat belts as the Boxster is mainly a daily driver and also can't find anyone doing a harness bar to fit in a Boxster.
Question to those of you with factory fit or retro fitted buckets, have you come across this and how did you address it? Does the factory use a similar method or does it use a different set of seat runners?
All help gratefully received
Yours
Chris
Background
I have a 986 Boxster S (2000) and love it to bits. Was thinking of trading in but I realised that the cash to change to would be very silly and quite honestly there's nothing I'd want to change it for in a fast 2 seater convertible kind of way apart from a newer Boxster S and even that would be second hand again. Knowing how I have maintained and looked after the car I therefore decided to throw some extra money at my own car and get a few things done;
1. Clear light upgrade
2. Change stereo to new Becker Cascade (booked into Prestige audio on Friday for this), and
3. Fit a pair of GT2 style buckets (just beacuse I want to and don't find the present seats as supportive and holding as my old Elise ones)
So I did my research and found the Deisgntek carbon fibre ones on design 911, ordered and all has gone smoothly with the order arriving in good condition an dexactly when delivery was promised. Now we come to the problem...
Problem
Upon fitting (by the chaps at GT One during his service) it looks as though the only way of getting the inside seat belt holder (i.e. the plastic clip that the metal tongue goes into) to fit is to bolt it to the outside of the seat using a small 8mm bolt. The original bolts to the runner using an approx 15mm bolt. Not happy with this new solution as am worried about securing my seat belt to such a small bolt. It looks like we can't attach to the original fitting and still be able to slide the seat back and forward (would need to as Mrs CVP is much shorter). No pictues yet as am work well away from the car. I need to retain the inertia reel seat belts as the Boxster is mainly a daily driver and also can't find anyone doing a harness bar to fit in a Boxster.
Question to those of you with factory fit or retro fitted buckets, have you come across this and how did you address it? Does the factory use a similar method or does it use a different set of seat runners?
All help gratefully received
Yours
Chris
On factory GT3 seats the buckle receptacle is bolted to the seat bracket (the verticle bit between the sliders and the seat body itself) and so slides fore and aft with the seat. The mounting point is reinforced.
I have a spare such bracket in my garage; send me an email via PH with your email address and I'll email you a photo. I'll also take dimensions of the seat mounting points to see if it's of any use to you.
I have a spare such bracket in my garage; send me an email via PH with your email address and I'll email you a photo. I'll also take dimensions of the seat mounting points to see if it's of any use to you.
Cheers chaps, am off to see Craig later to view the problem first hand and then a chat to Design 911. Looking like I am talking myself into getting harness bar and harnesses as well if this cannot be an easy fix
Email dispatched
Cheers
Chris
phelix said:
On factory GT3 seats the buckle receptacle is bolted to the seat bracket (the verticle bit between the sliders and the seat body itself) and so slides fore and aft with the seat. The mounting point is reinforced.
Yep, this is exactly as shown on the design 911 web site pic embedded. The worry is that the mounting is too small a bolt (8mm bolt instead of original 15mm bolt) Email dispatched
Cheers
Chris
Edited by CVP on Wednesday 7th February 14:13
The factory seat belt bolts are 7/16" UNF. There's a question for a pub quiz: what fasteners on a modern day 911 are UNF and not metric?
I would be more worried about what that seat belt bolt is screwed into than the bolt itself. There's probably a nut with some sort of sheet metal attached to it embedded in the GRP of the seat. Not sure I would want to trust that nut to retain the seat and the belt when things go wrong.
Photo of the factory bracket posted to your email address.
Hope this helps...
I would be more worried about what that seat belt bolt is screwed into than the bolt itself. There's probably a nut with some sort of sheet metal attached to it embedded in the GRP of the seat. Not sure I would want to trust that nut to retain the seat and the belt when things go wrong.
Photo of the factory bracket posted to your email address.
Hope this helps...
Edited by phelix on Wednesday 7th February 21:03
Looking at the picture you have posted I think I have exactly that seat and mount now fitted in my 993 (though my seat is alcantara/suede rather than leather). I too had a concern about the strength of bolting the seat belt buckle directly through to the carbon seat. I'm not sure if it'll be any help but the solution I came to is as follows:
1. I had a set of mounts fabricated that allowed the mounts to be bolted directly to the floor of the car without using sliding rails - this was mainly because I wanted the seat as low as possible.
2. the seat then bolts directly to the mounts (as per your picture)
3. I also had a new seat belt buckle arrangement made up with the buckle attached to about 4 inches of webbing then to the attachment "ring". My original plan was that the webbing would allow the buckle to be fed through the harness hole in the side of the seat and clipped in at that point. However, they are wearing bucket seats pretty tight about the hips this season, and its really not very comfortable. For now I'm leaving it outside the seat, but may have it remade with a longer piece of webbing which will allow it to sit above my hip bone.
4. the off side mount was then strengthened, drilled, tapped and a captive nut welded to the inner face. The seat belt buckle is then bolted to this with an M13 (approx, I think a previous poster gave the exact size) bolt rather then the M8s which is what holds the seat in. And its bolted to the mount - not to the seat.
Clearly the down side of this approach is that the seat has little or no adjustment once its in. This limitation is somewhat alleviated by having multiple holes in the mounts that allow siting of the seat in a number of positions. However, moving the seat more than about 20mm, takes around 20-25 minutes.
All in all I'm very happy with the arrangement. I only use it for track days so the limited adjustment is not an issue. You could certainly do something similar including the sliding rails if you have the height to play with.
I can't post you a pic now (I'm in New York at the moment) but can do so at the weekend if it'll help.
1. I had a set of mounts fabricated that allowed the mounts to be bolted directly to the floor of the car without using sliding rails - this was mainly because I wanted the seat as low as possible.
2. the seat then bolts directly to the mounts (as per your picture)
3. I also had a new seat belt buckle arrangement made up with the buckle attached to about 4 inches of webbing then to the attachment "ring". My original plan was that the webbing would allow the buckle to be fed through the harness hole in the side of the seat and clipped in at that point. However, they are wearing bucket seats pretty tight about the hips this season, and its really not very comfortable. For now I'm leaving it outside the seat, but may have it remade with a longer piece of webbing which will allow it to sit above my hip bone.
4. the off side mount was then strengthened, drilled, tapped and a captive nut welded to the inner face. The seat belt buckle is then bolted to this with an M13 (approx, I think a previous poster gave the exact size) bolt rather then the M8s which is what holds the seat in. And its bolted to the mount - not to the seat.
Clearly the down side of this approach is that the seat has little or no adjustment once its in. This limitation is somewhat alleviated by having multiple holes in the mounts that allow siting of the seat in a number of positions. However, moving the seat more than about 20mm, takes around 20-25 minutes.
All in all I'm very happy with the arrangement. I only use it for track days so the limited adjustment is not an issue. You could certainly do something similar including the sliding rails if you have the height to play with.
I can't post you a pic now (I'm in New York at the moment) but can do so at the weekend if it'll help.
tertius said:
may have it remade with a longer piece of webbing which will allow it to sit above my hip bone.
That sounds a bit scary too. I would rather the force exerted by my hip with the G-force in an impact was against a nylon strap than a buckle. The buckle on any harness is always sited next to a soft bit of the body, if adjusted correctly. I did know of a passenger with one that wasn't adjusted properly that hit the barrier near Knickerbrook - broke his sternum
. thegoose said:
tertius said:
may have it remade with a longer piece of webbing which will allow it to sit above my hip bone.
That sounds a bit scary too. I would rather the force exerted by my hip with the G-force in an impact was against a nylon strap than a buckle. The buckle on any harness is always sited next to a soft bit of the body, if adjusted correctly. I did know of a passenger with one that wasn't adjusted properly that hit the barrier near Knickerbrook - broke his sternum
. Which is why I said in my original post "for now its outside the seat" (or words to that effect) - ie its buckled between the seat and the transmission tunnel and due to the relative depth of the bucket and size of me, the seatbelt rests snugly across my lap. If I have it inside the seat it actually sits between me and the side of the seat so I don't think its dangerous its just uncomfortable. Getting a longer piece of webbing would allow it to rest across my lap and make use of a CGLock viable.
The seat mounting brackets that don't come with seat belt mounting holes generally assume the belts will be bolted to the chassis of the car. In road cars this is usually the case for the outboard mounting point but most cars have the inboard mounting point attached to the seat so that the buckle is always convenient for the user.
You might wish to look at brackets by Brey Krause www.bkauto.com/porsche/r9078.php They have a separate inboard seat belt mounting point on the bracket.
You might wish to look at brackets by Brey Krause www.bkauto.com/porsche/r9078.php They have a separate inboard seat belt mounting point on the bracket.
tertius said:
thegoose said:
tertius said:
may have it remade with a longer piece of webbing which will allow it to sit above my hip bone.
That sounds a bit scary too. I would rather the force exerted by my hip with the G-force in an impact was against a nylon strap than a buckle. The buckle on any harness is always sited next to a soft bit of the body, if adjusted correctly. I did know of a passenger with one that wasn't adjusted properly that hit the barrier near Knickerbrook - broke his sternum
. Which is why I said in my original post "for now its outside the seat" (or words to that effect) - ie its buckled between the seat and the transmission tunnel and due to the relative depth of the bucket and size of me, the seatbelt rests snugly across my lap. If I have it inside the seat it actually sits between me and the side of the seat so I don't think its dangerous its just uncomfortable. Getting a longer piece of webbing would allow it to rest across my lap and make use of a CGLock viable.
Sorry, I may have misunderstood what you meant. These things are difficult to communicate without pictures I guess - you describe something you have seen and I have to create an image in my head based on my understanding of that. I was thinking you meant the buckle would sit on the front of your hip bone so that your hip would be thrown into it in a frontal impact, which should explain why I thought it sounded a bit scary.
thegoose said:
Sorry, I may have misunderstood what you meant. These things are difficult to communicate without pictures I guess - you describe something you have seen and I have to create an image in my head based on my understanding of that. I was thinking you meant the buckle would sit on the front of your hip bone so that your hip would be thrown into it in a frontal impact, which should explain why I thought it sounded a bit scary.
Understood
- if this thread is still going when I get home at the weekend I'll post a picture.steil said:
An alternative approach would be to bin the standard belts & replace with say Schroth retractable harnesses. These can be mounted to eyelets to ensure safety, and as they're retractable you have the flexibility you have with a 3-point belt but with a 4-point harness.
Cheers, might be a way forward but I was hoping not to incurr so much additional expense.
The update is replacement seat mounts / sliders are on their way and we'll see if this is a good solution.
Cheers all for the input, much appreciated
Chris
An additional update
1. Replacement sliders (at no cost) arrived as promised but exactly the same mounting as the first set i.e. bolt seat belt retainer to the seat mount with 8mm bolt. This was after me specifically stating when ordering the replacement sliders that we were not happy with the security of fitting the inboard seat belt retainer with such a small bolt.
2. I met up with fellow Ph'er Phelix who had a spare factory set of runners and these did not fit the bolt spacing on the new seat, factory fit spacing on the seat bolts is 264mm, the Designtek seat has a bolt spacing of 276mm.
3. Confirmed with the guys at Brey Krauze that their mounts also had a different bolt spacing to my seat. Their factory fit one is obviously 264mm (part R-9078) and for the Recaro / Sparco fit ones it is 289mm (part numbers R-907*).
The long and short of this is seats and two sets of sliders are to be sent back tomorrow and let's see how the supplier reacts to my request for some kind of assistance with the cost I've incurred on the abortive fitting.
So I'm back to square one on the seat front and I suspect my best option now is to bite the cost bullet as I see Southbound will supply OEM GT2 style buckets and runners. It's a real shame as the Designtek seats look absolutely great with their carbon backs and are comfy and a good size. If you were looking to go with a harness and did not need to mount an inboard seat belt retainer but had the harness bolted elsewhere e.g. direct to the tunnel then these seats are really nice.
Chris
1. Replacement sliders (at no cost) arrived as promised but exactly the same mounting as the first set i.e. bolt seat belt retainer to the seat mount with 8mm bolt. This was after me specifically stating when ordering the replacement sliders that we were not happy with the security of fitting the inboard seat belt retainer with such a small bolt.
2. I met up with fellow Ph'er Phelix who had a spare factory set of runners and these did not fit the bolt spacing on the new seat, factory fit spacing on the seat bolts is 264mm, the Designtek seat has a bolt spacing of 276mm.
3. Confirmed with the guys at Brey Krauze that their mounts also had a different bolt spacing to my seat. Their factory fit one is obviously 264mm (part R-9078) and for the Recaro / Sparco fit ones it is 289mm (part numbers R-907*).
The long and short of this is seats and two sets of sliders are to be sent back tomorrow and let's see how the supplier reacts to my request for some kind of assistance with the cost I've incurred on the abortive fitting.
So I'm back to square one on the seat front and I suspect my best option now is to bite the cost bullet as I see Southbound will supply OEM GT2 style buckets and runners. It's a real shame as the Designtek seats look absolutely great with their carbon backs and are comfy and a good size. If you were looking to go with a harness and did not need to mount an inboard seat belt retainer but had the harness bolted elsewhere e.g. direct to the tunnel then these seats are really nice.
Chris
In case its any help here is a pic of the modified seat mount I'm using:
I'm 99% certain this is the same mount/seat you have. The mount has been lengthened (simply by welding a bit on the front
) and then a seat belt mounting point has been fitted directly to the mount by strengthening the back of the mount and a nut welded to it. The seat belt buckle and webbing was specially made for this seat/mount arrangement but you can probably use your existing seat belt buckle.
Since you are using the sliders you won't need to lengthen the mount and simply need to get the belt anchor point attached to the mount. My usual indy did this for me (it cost quite a bit because we had the whole lengthening and general b*ggering about to do - bet it would be peanuts if you are just adding the anchor point).
Feel free to PM me if you want more pics and details.
I'm 99% certain this is the same mount/seat you have. The mount has been lengthened (simply by welding a bit on the front
) and then a seat belt mounting point has been fitted directly to the mount by strengthening the back of the mount and a nut welded to it. The seat belt buckle and webbing was specially made for this seat/mount arrangement but you can probably use your existing seat belt buckle. Since you are using the sliders you won't need to lengthen the mount and simply need to get the belt anchor point attached to the mount. My usual indy did this for me (it cost quite a bit because we had the whole lengthening and general b*ggering about to do - bet it would be peanuts if you are just adding the anchor point).
Feel free to PM me if you want more pics and details.
cvp said:
An additional update
1. Replacement sliders (at no cost) arrived as promised but exactly the same mounting as the first set i.e. bolt seat belt retainer to the seat mount with 8mm bolt. This was after me specifically stating when ordering the replacement sliders that we were not happy with the security of fitting the inboard seat belt retainer with such a small bolt.
2. I met up with fellow Ph'er Phelix who had a spare factory set of runners and these did not fit the bolt spacing on the new seat, factory fit spacing on the seat bolts is 264mm, the Designtek seat has a bolt spacing of 276mm.
3. Confirmed with the guys at Brey Krauze that their mounts also had a different bolt spacing to my seat. Their factory fit one is obviously 264mm (part R-9078) and for the Recaro / Sparco fit ones it is 289mm (part numbers R-907*).
The long and short of this is seats and two sets of sliders are to be sent back tomorrow and let's see how the supplier reacts to my request for some kind of assistance with the cost I've incurred on the abortive fitting.
So I'm back to square one on the seat front and I suspect my best option now is to bite the cost bullet as I see Southbound will supply OEM GT2 style buckets and runners. It's a real shame as the Designtek seats look absolutely great with their carbon backs and are comfy and a good size. If you were looking to go with a harness and did not need to mount an inboard seat belt retainer but had the harness bolted elsewhere e.g. direct to the tunnel then these seats are really nice.
Chris
1. Replacement sliders (at no cost) arrived as promised but exactly the same mounting as the first set i.e. bolt seat belt retainer to the seat mount with 8mm bolt. This was after me specifically stating when ordering the replacement sliders that we were not happy with the security of fitting the inboard seat belt retainer with such a small bolt.
2. I met up with fellow Ph'er Phelix who had a spare factory set of runners and these did not fit the bolt spacing on the new seat, factory fit spacing on the seat bolts is 264mm, the Designtek seat has a bolt spacing of 276mm.
3. Confirmed with the guys at Brey Krauze that their mounts also had a different bolt spacing to my seat. Their factory fit one is obviously 264mm (part R-9078) and for the Recaro / Sparco fit ones it is 289mm (part numbers R-907*).
The long and short of this is seats and two sets of sliders are to be sent back tomorrow and let's see how the supplier reacts to my request for some kind of assistance with the cost I've incurred on the abortive fitting.
So I'm back to square one on the seat front and I suspect my best option now is to bite the cost bullet as I see Southbound will supply OEM GT2 style buckets and runners. It's a real shame as the Designtek seats look absolutely great with their carbon backs and are comfy and a good size. If you were looking to go with a harness and did not need to mount an inboard seat belt retainer but had the harness bolted elsewhere e.g. direct to the tunnel then these seats are really nice.
Chris
why not just redrill the part you have and make sure you use some decent oversize washers to spread the load?
[quote=fergus
why not just redrill the part you have and make sure you use some decent oversize washers to spread the load?
[/quote]
I guess maybe I'm a bit too cautious with something potentially this important. For anything safety related I want to be 100% sure in my own mind that I'm OK, with these sliders everything has needed washers here and there to fit and that leaves me a little uncomfortable.
If I was younger and single I might take the risk but I couldn't live with myself if Mrs CVP was blatting along and had a big off and came to harm for something where I was not 100% happy with the fitting (yes I am a soft old git where she is concerned).
Chris
why not just redrill the part you have and make sure you use some decent oversize washers to spread the load?
[/quote]
I guess maybe I'm a bit too cautious with something potentially this important. For anything safety related I want to be 100% sure in my own mind that I'm OK, with these sliders everything has needed washers here and there to fit and that leaves me a little uncomfortable.
If I was younger and single I might take the risk but I couldn't live with myself if Mrs CVP was blatting along and had a big off and came to harm for something where I was not 100% happy with the fitting (yes I am a soft old git where she is concerned).
Chris
cvp said:
fergus said:
why not just redrill the part you have and make sure you use some decent oversize washers to spread the load?
I guess maybe I'm a bit too cautious with something potentially this important. For anything safety related I want to be 100% sure in my own mind that I'm OK, with these sliders everything has needed washers here and there to fit and that leaves me a little uncomfortable.
If I was younger and single I might take the risk but I couldn't live with myself if Mrs CVP was blatting along and had a big off and came to harm for something where I was not 100% happy with the fitting (yes I am a soft old git where she is concerned).
Chris
I really can't see your concern if you attach the seat belt mounting direct to the seat mount as I described - those mounts are pretty chunky - certainly more substantial than the original Porsche seat rails.
tertius said:
I really can't see your concern if you attach the seat belt mounting direct to the seat mount as I described - those mounts are pretty chunky - certainly more substantial than the original Porsche seat rails.
You're right, your solution looks like it could work very well and would be strong enough. One for me to investigate
Cheers
Chris
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