Late seats in an early car...Adapters? Seatbelts? Safety??

[Tremelune]

I have a 1970 911T with aftermarket seats that I think are too firm. I picked up a set of tombstone seats from a '75 911 to tide me over until I can find someone who will make me custom ventilated seats. Looking at the bracketry involved, this seems more involved than anticipated, and I'm wondering if should punt.

Is it okay for seats to be mounted with small bolts like this? In my mind, the mounts for the seatbelts are what take the force in a collision, and seats could more or less be held in with velcro. that said, there was once a shop that was scared to give me back my (different) car when they found the seats weren't mounted with those 1/4" thick washer plates that spanned two mounting bolts. What's the right way to mount seats?

With regard to the seatbelts...I was hoping to replace my stock belts with a reel set from Seatbelt Planet. I don't love the behavior of the stock belts, and I'd rather have belts that weren't 50 years old. The L-brackets I have seem...inadequately mounted, but I don't know what the 7/16-20 equivalent is in two-bolt form...Are these L-brackets mounted safely?

I can cut/drill my own adapters from 1/4" steel stock or whatever, but I'd like to avoid welding that tunnel...and I'd also like to make sure I'm not losing safety/strength due to ignorance.

[Tremelune]

Mm, I'm noticing that a reel would require high and low 7/16-20 mounts, and this car only has the high mount (the low mount is the L bracket attached)...That would put the reel right next to the seat, which might be...goofy...

Grumble, grumble...

[Lz7w]

I had a set of later (76 I think?) seats in my '70 when I bought it. you need a set of adapters that attach to the 8 mounting points on the car (tunnel and the outer seat mounting bracket) because the later seat has a narrower mounting width (roughly 2" from memory, but I'm happy to send you pictures of the brackets if helpful).

the seat sliders were mounted to the adapters with bolts and lock nuts. once you have the sizing for the brackets, getting the seats in place should be pretty simple.

hope that helps!

[Hi_Fi_Guy]

Look inside the rear fender for a bolt approximately rear seat cushion height. If you see it you can remove this bolt. Then pull the upholstered rear side panel from the interior and find the hole where you just removed the bolt. This is where the seat belt inertia real bolts in. Several vendors offer aftermarket seat belt kits that will work. Perfect fit and easy install too.

[Robert Adams]

I'm having my not so comfortable '73 comfort seats rebuilt and I'm installing a set of Recarro LS seats for now. I had my factory seatbelt reals rebuilt last year and they work great...like new! I'll search for the receipt and post the source shortly.
Installing the LS seats, I'm using a similar seat frame as in your picture. I just did a mockup install and the washers definitely need to be thicker....so I reused the factory double hole washers as pictured. Had to slightly elongate the holes because they don't line up exactly, but they're very close.
May find or make a set for the seatbelt brackets as well. I was torn between attaching the brackets to the seat like the factory does or to the frame? Seems to me, the frame would be more secure.

[Robert Adams]

[Tremelune]

You're telling me that if I scrape off the undercoating and remove this bolt, this is the threaded hole that reels are bolting into??

[rothaus]

Originally Posted by Tremelune

You're telling me that if I scrape off the undercoating and remove this bolt, this is the threaded hole that reels are bolting into??

Correct, there you can mount the new seatbelt. There is maybe just a plastic plug. That is where I will install a new retractable belt in my 71.

Cheers
Engelbert

[HarryD]

my Story for my 1973.5 with 1977 seats: http://forums.pelicanparts.com/porsche-911-technical-forum/191185-seatbelt-attachment-late-seats-early-car.html

more info: https://forums.pelicanparts.com/porsche-911-technical-forum/676914-85-seats-72-a.html#post6741184

[Hi_Fi_Guy]

Originally Posted by Tremelune

You're telling me that if I scrape off the undercoating and remove this bolt, this is the threaded hole that reels are bolting into??

Yes, and several aftermarket suppliers sell seatbelt kits with all the hardware and instructions you need. Super quick and easy.

[Hi_Fi_Guy]

I looked in my records. The seatbelt kit I used on my 71 Targa was from Peparts KT101T. The seatbelt retractor reels hide behind the rear side trim panels on the targa. The stock L brackets are used for the mounting points at the seat.

https://www.peparts.com/front-seat-belts/kt101t-911-and-912-targa-model-1969-73-with-stock-seats

[Tremelune]

This is handy.

Current plan is to make adapters from some 1/4" steel plate that I will tap and thread for the two bolts used in each L bracket, and use a 1/8" plate for the top of the L bracket to ensure the bracket doesn't just rip out past the bolt heads...

Bolts will be M6-1.0 all around (as they are now), but 12.9...

Seatbelts I'll deal with when the seats are in...

[3rd_gear_Ted]

The G-body tub seat belt nut inserts are SAE threads.

[HarryD]

Originally Posted by 3rd_gear_Ted

The G-body tub seat belt nut inserts are SAE threads.

FWIW. ALL seat belt hardware world wide is SAE 7/16 UNF. Some will have metric instead of a SAE bolt head.

Trivia: where is there always wood on a submarine?