[mjd23]

I removed the rear seat delete and would like to add lap belts (like the way it looks and a little lighter). I dont see tapped holes in the center of the car where one end of the lap belt connects. The other end of the lap belts bolt into the tapped holes for the rear seat delete. Did they not add this tapped hole for cabs at the factory? I poked around the area where I thought it would be (looking at pics of other 968/944s2 that have rear seat belts) with a very very small diameter punch through the carpet and didnt locate one. Do I need to drill and tap the holes?

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[flash]

they deleted the tapped holes later in the run.  yours is a 95.  it won't have the holes.

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[mjd23]

Ok, thanks for letting me know.

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[mjd23]

Has anyone added the interior tapped holes? Is the metal thick enough to drill and thread or do I need to just drill a thru hole and use jumbo washers with lock nuts? Can I access the backside to install washers & nuts? Do I need to worry about drilling into/ thru anything?

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[94SilverCab]

I've been trying to confirm, but I don't think you'll have any issue since they were factory designed with seat belts for ROW cars.

 

Jay

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[mjd23]

Yeah, thats my guess as well. Cost reduction by not drilling and tapping the hole makes sense but seems unlikely that the material thickness would change. Probably more work than what it was worth to make thinner but try to keep same structural stiffness.


Thank you for the feedback.

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[Waylander]

I bet there is a nut or threaded collar welded into the floor on the earlier cars, just the thin steel on its own will not be strong enough for a seat belt anchor point

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[mjd23]

Good point. I didnt think of a weld nut option or a separate threaded thick washer.

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[flash]

regardless of whether or not you install those lap belts, the rear seats will not be legal for use in the US, due to the lack of a shoulder harness, which is required on all cars newer than 1983.  they could not install one on the 968 cab, due to the lack of a mounting point high enough to not take the head off the occupant in an accident.  canada and the ROW did not have the crash tests the US had.

 

yes, i know people have done it.  yes, i know we all drove around for decades with only lap belts (when we actually even used those).  that does not change the fact that it is illegal and dangerous in the 968 cab.

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[mjd23]

Understood. I just prefer the look of the rear seats and want the look as authentic as possible. I dont plan to have riders in the back. Having said that, you could install a 4 point seat belt just by adding a third attachment point in the trunk behind the back rest (typically near the wheel well). There are installation kits for it that are both safe and legal. Just comes down to preference and how you want to use the car.


Anyone have dimensions to the inner hole say from the carpet line and seat floor? Is it basically in the same position as the outer holes for the rear seat delete? I would like to locate the hole in same spot as manufactured in case the next owner wants to install 944 s2 seats instead.

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[flash]

one of my biggest regrets was removing the storage boxes.  those were incredibly useful.  ironically it was one of the features that drew me to the car in the first place.  i remembered them from a couple of other cars, and loved them.  then i installed the subwoofer, and deleted them.  i never really got over the loss of those though.  it was so much easier to lock them, than to have to remove what ever was in the car, and put it in the trunk.

 

as for the seat belts, i think you would have to drop the fuel tank, just to get to the spot you are talking about, and i don't think you could mount them high enough to avoid spinal compression.  there is a limit to how low you can mount the 3rd point, without risking spinal compression.  if you read the instructions, and also understand how belts are mounted and designed, the rearward strap has to go over the top of a seat, at or above the shoulder, which avoids the spinal compression issue.  there is no seat back over which you could run the belt, that would be higher than the shoulder.  the seats are just too high, relative to any rear anchor point or passover point.

 

as for authentic, the car was never offered with those seats in the US, so i think you are departing from that. it would also raise the question of liability, if you install something and in any way led the next owner to believe it was safe.  contrary to popular belief, the seller is still liable in the event of an accident, if they can be proven to have contributed to the damage or injury as a result of their actions.  the only way to avoid that would be to remove the seats prior to sale.

 

all that being said, i understand the desire for more storage space, and the storage boxes limit what you can carry back there. in the white car i just left it exposed carpet (the previous owner had buggered the storage boxes).

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[mjd23]

Yes, I read the instructions. Spinal compression lol? I think you’re reaching a bit. I didn’t ask for your opinion if you liked the idea or not. I was asking for feedback about a hole location. It would be great if folks could keep the conversation technical instead of personal. I’m not throwing out the box just because I removed it. I like having the option.

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[94SilverCab]

Yes, I read the instructions. Spinal compression lol? I think you’re reaching a bit. I didn’t ask for your opinion if you liked the idea or not. I was asking for feedback about a hole location. It would be great if folks could keep the conversation technical instead of personal. I’m not throwing out the box just because I removed it. I like having the option.

 

Pay no attention, he gets a little full of himself. Knows a helluva lot about 968s though, so we let him stick around.

 

Jay

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[flash]

spinal compression is a very real and very dangerous thing.  i suffered a spinal compression injury as a result of a poorly mounted belt, that to this day, 30 years later, still bothers me.  i know what i'm talking about.  ask anybody who has set up a race car about harnesses and their mountings and how important they are, and the very specific rules about them.  they exist for good reason, as do the design requirements placed by DOT.  you would almost be better off with no belt at all, than a shoulder belt that compressed the spine in an accident.  that is why all shoulder belt mounting points are either very high, or take the belt over the top of a seat at or above shoulder height.

 

by the way, the sheet metal at the lap belt mounting point is reinforced in early cars.  if it is not there on yours, simply drilling a hole and putting in a bolt will not hold in an accident.  i'm also not sure the area is flat.  you will at least need to use very large fender washers to spread the load out  (as an engineer, i could calculate the size, but it doesn't seem like that would be prudent).  if it is curved, that changes the design of the backing material.  i'm not sure you will have access though to where the mounting point is, due to the torque tube being right there.  that could prove to be a challenge.

 

as for the rest, do what you want.  it's not about you though.  our responsibility here on this site is to provide that others should also be aware of and understand the pros and cons of any modification.  i was merely offering advice based on wisdom gleaned from experience.  take it.  don't take it.  i don't care.

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[MCL968]

Good points Flash. If I am going to do something risky, I make sure I am the one at risk. When I raced, I took the risks, when I crewed, I never let the driver take risks for me.

 

I suppose the question is who will be using those belts? If MJD is riding in the back, it's his business. If it's someone else, different story.

 

FYI, my early 92 has the attachment points. If I recall correctly, they are reinforced and seemingly very different from the surrounding metal.

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[flash]

unfortunately i have nobody to blame for the injury but myself.  i also had nobody to sue.   i installed shoulder belts in my mgb and mounted them too low. i didn't know any better at the time.  when i crashed the car, it threw me forward, and the belt pulled down on my shoulders and squished me down.  this compressed 2 disks.  i was in traction for a while, and narrowly avoided surgery, though i may yet have to undergo that, as it is getting worse. to this day it bothers me, to the point of putting me in bed a couple of days a year when i over-exert myself or even spend too much time standing on a hard surface.  i eat ibuprofin like candy.  it really sucks, but it's better than being paralyzed, as i have heard can happen with this type of injury.

 

everybody is free to do what they want.  the best i or anyone can do, and all should do as a matter of conscience, is make people aware when there is a risk.

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[mjd23]

If you bothered to read the post, I said I like the look of it. I also said no one is riding in the back. Don’t put words in my mouth. Just because you got yourself hurt due to a poorly mounted belt doesn’t mean everyone else can’t figure out how to install them safely or that they will have the same outcome. I’m not throwing in rear seat lap belts and taking it Formula one racing with my family in the back. If or when I sell my car I will remove them and reinstall the box I didn’t throw out.


Sticking to factual information not unsolicited opinions/advice, you don’t need to be an engineer to know stress = F/A. They sell retrofit kits with grade 5 washers, bolts, and lock nuts. The washers provide the added reinforcement if the sheet metal is thin. Grade 5 washers are rated to 85ksi for yield and 120ksi to ultimate fail. Area of a circle is pi*diameter squared/4. Substitute that in the previous equation and solve for the diameter. D=sqrt(4*F/(pi*stress)). If assume worst case recorded formula one crash of 217gs, 200lb driver, and 85ksi washer, and all that load is applied to one mounting point, the required minimum diameter is 0.8”. The fender washers supplied in the retrofit kits are 3” or about 4 times larger than required to survive the worst case formula one crash. If you need a rectangular washer to fit the available area, then perform the same calculation except area is length*width. I would say the kits are more than adequate and I wouldn’t hesitate to use one.


Regarding your advice...you say your commentary is for the good of the forum except you continuously reference yourself as all knowing and provide unsolicited negative commentary based on your opinions. How noble. I wouldn’t pull and scrap the box to put a subwoofer in the back like some 16 year old kid with his first car either but I’m not going to jump down your throat about if you want to. I was asking for info before I just wrecklessly start ripping into the carpet or drilling holes. I don’t know every last detail of this car and I’m not trying to pretend to. I asked for information, not your advice or opinion. I thought that was the point of this forum. I didn’t join it so I would have to put up with with your blowhard commentary.

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[flash]

where did i put words in your mouth?  i think you are reading entirely too much into what i wrote.  this is not a two way conversation.  this is an open discussion forum and comments are to all members, not just one.  i am stating facts and presenting information.  what one decides to do with that is up to the individual.  THAT is the point of the forum.

 

while not accounting for the thickness of the sheet metal or the angle of force applied, yes, a .06" thick washer of 3" diameter is likely okay, assuming the washer makes full and even contact, which i do not think it can do in that location.  you could make your own though, and form it to the contour, assuming you can gain access.  i've used those kits, and they are adequate, assuming that they are properly installed, torqued, and loctite is used, in addition to lock washers.  of course, unless you use a shoulder bolt, this does present a potential swivel issue, which could render the belt itself at risk.

 

regarding my advice, for those new here, i'll try to give a little history.  i essentially started this website.  i took over this site over a decade ago.  i built it up to what it is today.  i've been here longer than anyone else, and have been the most active member.  i owned and operated the world's largest aftermarket parts company for the 968 for over 10 years.  i would not say i am all knowing, but probably as close as anyone gets about this car.  i feel that my counsel has merit and value, however, i do not insist that anyone heed it, and often am certain that they won't.  that's ok.  i've still done my due diligence.  one of the mantras at the establishment of the site was to inform the members about anything and everything, so they can make their own informed decisions.  that is not going to stop because any one member wants to do something, and might not like to hear dissenting opinion.  it is the responsibility of the management to do everything within their power to present all perspectives and views, and promote discussion and informational exchange.

 

again, anyone is free to do whatever they want to their own car.  something often not considered though is that this is a small community, and we all remember everyone's car.  when it comes time to sell or buy a car, its provenance can come into play.  hence some of us will offer advice regarding changes.  i am a huge fan of mods.  some guys are not, and won't touch a car that has any.  i've had both extreme ease and extreme difficulty when selling a car with mods.  you just never know.  that wasn't the point of my comments though.  as with any mod, i was merely presenting potential issues or complications, so that members can make their own decisions.

 

as for this particular mod, i really could care less.  i really don't have an opinion.  it really wouldn't matter anyway.

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[ds968]

To mjd23 - relax ! Take both the technical advice as well as the personal opinions and experiences of the members of this forum for whatever they're worth to you, and then make up your own mind .

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[ds968]

..I've been here longer than anyone else .

As for you young man, methinks you're wrong ; I've been here ( well , starting with the original 968.net ) before you even owned a 968 , and subsequently took over this forum from the original founders ..the profile shows me joining one month after you in 2005 , but that's an error ..I was definitely here first, so respect your elders dammit , lol !

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