Seat Belts - 72 Targa with 82 Sport Seats

techguy · 03:41 PM

Hey guys,

Just spent the last hour reading past seatbelt posts. It appears that I am not alone in this long standing dilema. According to the posts in 1972 the front seat belt receiver was mounted to the seat, the chest belt to the upper targa bar and the retractor did not exist since the belts hung on a clip near the back window when one got out.

I spoke to a few folks locally today and learned that a retractor will not fit in the 72 Targa's inside rear quarter panel insert only .5-1" deep. I was also told that the receiver should not be mounted to the seat rails since 6mm nuts are not strong enough.

What is my solution? Here are some pics, the areas of concern (marked) sit below a rectangular ~ 2 foot by 2 foot .25" sheet of plate steel that the seats bolt to. Am I over reacting or do I need a better setup? Remember these are later seats in an early car so the sheet of plate steel is a bit of an overkill but a decent adapter.

techguy · 03-30-2004, 03:46 PM

Here are the pics:

HarryD · 03-30-2004, 04:41 PM

Quote:

Originally posted by techguy
Hey guys,

Just spent the last hour reading past seatbelt posts. It appears that I am not alone in this long standing dilema. According to the posts in 1972 the front seat belt receiver was mounted to the seat, the chest belt to the upper targa bar and the retractor did not exist since the belts hung on a clip near the back window when one got out.

I spoke to a few folks locally today and learned that a retractor will not fit in the 72 Targa's inside rear quarter panel insert only .5-1" deep. I was also told that the receiver should not be mounted to the seat rails since 6mm nuts are not strong enough.

What is my solution? Here are some pics, the areas of concern (marked) sit below a rectangular ~ 2 foot by 2 foot .25" sheet of plate steel that the seats bolt to. Am I over reacting or do I need a better setup? Remember these are later seats in an early car so the sheet of plate steel is a bit of an overkill but a decent adapter.

Hi,

Interesting.

My '73 retractors are in the rear quarter panels. with the D ring guide mounted on the targa bar post.

I am not a mechanical or structural engineer, but I would think that the bolts used to attach the adapter plate to the existing mounting points would be ok since that is how the orginal seat (with integral seat belts) was also restrained. If you want a bit of extra insurance, be sure you use some 8.8 rated bolts for the hold downs.

My plates (from PE Products) are made of 1/4" steel, so you should be ok there with your material selection.

Hope this helps a bit.

jasonq · 03-30-2004, 05:08 PM

Ditto to harry on the location of the retractors in my 73 as well.

one word of caution, be very careful not to use bolts that extend into the tunnel farther than the OEM bolts. the fuel lines (at least on CIS) run in the upper drivers side corner of the tunnerl, right below the seat bolts. I didnt know that, and punctured a fuel line. Not a good scene, and $500 to fix.

That said, I am a mechanical engineer, and mounting to that spot should be very similar to the stock mounting.

first rant follows: I would defintiely use plate on top of the seat belt "L" instead of using washers. Since the "L" will be farther back than stock, I would also be careful about how the "L" lines up to with the belt, basically that it is in line with the belt. What i am specifically worried about is it constantly being pulled and bent/twisted, leading to fatigue cracks starting over a long period.

second more tedious rant follows: but it is different than the factory belt mount method. The factory mount location is to the rearish of the seat bottom. Depending on where you adjust the seat, it is likely to be in between the front and rear seat rail bolts. hence the load will be shared between then differently based on seat location. This applies in the upward direction. In the left/right direction, load is shared by the seat rail bolts in a similar manner as vertically. In the fore/aft direction is is the fore/aft seat adjuster/plate that does the work. I don't remember how many bolts hold the slotted plate to the tunnel. note that the adjuster takes the load from both sides of the lap belt, while you are spreading the load to both sides.

jason

vol96 · 03-30-2004, 06:18 PM

I had a 72 coupe and now have a 73 targa. Both have retractor in rear quarter panel. I could get you pics of my 73 retractor mount.....currently have trim off.

Your mounting locations seem fine...in areas that have thick metal. I would try to use bolts bigger than the allen bolts that attach the bottom slider to the rail.

BTW, have you mounted the seats yet? I'd like to see how that is done as I am interested in later model seats for my 73.

techguy · 03-30-2004, 06:31 PM

Some pics of the retractor mount would be great, I just don't see any depth aside from maybe .5" inside the panel. I did find a point of strength behind the panel with a plug that travels to the rear wheel well but the inset in the area would hardly hold a retractor, at least the ones I have seen on the bbs.

Thanks!!

fintstone · fintstone's Garage

techguy · 03-30-2004, 07:23 PM

Hey Flintstone!

Thanks for the pics, I assume those retractors are in the panel right? Just how wide would they be?

fintstone · fintstone's Garage

fintstone · fintstone's Garage

as measured with a cheap ruler and not a micrometer

fintstone · fintstone's Garage

techguy · 03-31-2004, 04:26 AM

Thanks Flintstone again for the pics, you confirmed my fear. I have aprox 3/4" depth in that area and nothing to attach to unless I go with an external mount. Looks like the 72 and earlier cars since they came with non-retractors have no cavity in the rear quarters. I also have an oil tank in the passenger cavity, a unique feature of this year also. I noticed in Tweeks that they have an externally mounted retractor maybe I'll give them a shout today. After a bit of research I traced the belt system I currently have down to a 1980 Rabbit, maybe a start for a floor mounted setup.

Thanks again!

fintstone · fintstone's Garage

Note that the depressions where my retractors mount are not very deep and the covers bulge out a bit near the bottom to compensate.

techguy · 03-31-2004, 06:04 AM

Maybe that is the key, a buldge in the covers. I have skins from a 68 or 69 in the rear so they are completely straight. Maybe if I go with a later style? What about the receiver, I need one with an eye in it to attach to my adapters.

fintstone · fintstone's Garage

The panels don't truly have a bulge made into them..they are straight, but flex outward at the bottom to create a slight angle. These are matching receivers:

HarryD · 03-31-2004, 06:30 AM

Quote:

Originally posted by techguy
Maybe that is the key, a buldge in the covers. I have skins from a 68 or 69 in the rear so they are completely straight. Maybe if I go with a later style? What about the receiver, I need one with an eye in it to attach to my adapters.

techguy,

I used the original system for my '73. I mounted both the belt end and the '73 receiver of the lap belt points to the "ears" on my plates. I was very nervous about drilling into the tunnel.

I am not near my car right now but I can post a few pics this weekend.

I also seem to remeber the slight bulge that flintstone is referrring to as well.

techguy · 03-31-2004, 06:41 AM

Ok, I will play with the idea of retractors in the Targa bar area. I think I may take off the passenger side panel to see if the oil tank is in the way. Flintstone, could you pull the receivers from the centre boot as depicted in your picture? It sure looks a lot like mine.

fintstone · fintstone's Garage

Yes, but you might ruin the boot. The rubber is probably a bit brittle for most.

techweenie · techweenie's Garage

Tech guy: my '72s have all had the retractors in the inner rear panel, which makes me think the fittings are there in ROW cars, if I understand your situation correctly.

I've put aftermarket seats in several '72/73 cars and have used a 12-gauge steel adapter plate of my own design for the seat mount. I make it 1/2" longer toward the rear, use the rearmost allen head bolt on the front part of the stock mount and make a second hole with proper spacing for the stock mount, and run a bolt up from underneath the adapter plate for the rear hole. I can shoot a picture in a few days if that helps...

Oh, and one other thing: the hole in the 'tongue' of the seat belt -- where it goes into the receptacle -- is larger on a '72 than on a '73 and later, so test the receptacles to be sure they work with your belts before you mount them!

techguy · 03-31-2004, 07:20 AM

Ok, took off the insulation and this is what I have (pics below). I see 1 plug here. I like the idea of creating a better adapter for the receivers and I think I may just take the receivers out of a later boot and attach each one separately to an adapter below the seat made out of a higher grade of steel. Looks like my quarter panels bow into to cavity v.s. out so I might need some later style panels or cut the indenet of of mine.

Does the retractor require 1 or 2 bolts to the body?