MyRed69

I fixed some cracks in my '69 floorboard, took out the under-mount reinforcements, sandblasted and powdercoated some and replaced the others. As I started replacing them I started to wonder my question is this; does anyone have experience or knowledge of the durability of the fiberglass floor during an accident? It just seems a little too flimsy a setup, like those mounts would just pull through the floor (and the wheel well for the shoulder mount) in the event of a 'sudden stop' and my fat a$$ yanking on them at 50 or 60 MPH. I'm sure those smart GM engineers took all that into account, but... Just wondering.

Alan 71

Hi MR69,
I'm not sure just how your 69 is built.
On my 71 the outer belts bolt to nuts welded to the sill portion of the birdcage and the inner belts load is passed by a bolt to the u-bracket in the tunnel and through 2 cables to the cross-member. The shoulder belts mount to a nut on a plate that has about 40 sq inches of surface contact with the wheel well in 2 planes.
The loads for the seat mounts seem to be spread over the fiberglass floor by plates also, especially the front mounts.
Certainly cars designed in the sixties are very different than today's cars in occupant crash protection.
" Ban low performance drivers NOT high performance cars". The speed shop I frequented in the late sixties use to give out bumper stickers with that on them.
Regards,
Alan

U17

I've been thinking about that alot after a deer collision on Thanksgiving day.. We were in the GF's new,2400 mile, Lacrosse.. Did the 70 to 0 demostration... About three car lengths... Airbags ,OnStar ect all worked great. On my '76 I have four point Simpson harness'... Picked up the factory side mounts but just a bolt and large washer for the shoulder harness. Thinking that the washer looked large at the store but should be HUGE !!!

MyRed69

After thinking about it I believe I was more concerned about the seat than was needed; it's the seat-belt that will do most of the work. If I remember correctly it does go through the birdcage on the drivers side. I do plan on upgrading the seats and belts. Since it's apart and I have access I'll add some type of backing plate to connect a four point harness. It still amazes me the seats are only mounted to small 1X2 inch pieces of metal (the arrow in the pic)


The powder-coated seat-belt parts -- plus some others.

zwede

There's no reason for the seat to be mounted stronger than it is. In the case of a crash the seat is just along for the ride. Not much force acting on it.

The seat belt is what takes up all the force. (Or, if you're foolish enough not to wear it, the windshield).

I'm not worried about the lap mounting points. One end into the birdcage (metal), the other has the cable and hook under the tunnel. The weakest point is probably the shoulder mount, but I guess it is also the one seeing the least force?

bucky-katt

wait................the floors are fiberglass? i havent really spent any time under mine yet. every time i come on here i learn more and more about them. found out about "birdcage rust" tonight too. i'm scared.

eagle275

better check mine.

BenUK

Only fibreglass up to late '75 (I think), when they became steel. Ask me how I know.

Easy Mike

Look at it this way...if you hit something hard enough to tear the seats out of the floor, it's not going to make any difference to you.

Know whut uh meen?

bucky-katt

wonder what the floors in my 78' are going to look like...............i REALLY dont have the place to pull the body. my shop is a small shop set up for motorcycles, i do all my work in the driveway.

Easy Mike

Crawl under and take a look. You can also peel back a corner of the carpet in places.

bucky-katt

if it isnt too cold i'm going to do bushings, wheel bearings, u-joints and pinion seal this weekend, i'll get a phillips head screw driver and poke at the boards.

dar322

Hey Bucky, if your going to do bushings, bearings, u-joints and pinion seal, you may need more than a weekend to complete. We'll look for an update on Monday.