What gauge metal for new seat rail supports?

Fab64 · Fab64's Garage

Hi all,

I've been researching how to lower the driver's seat in my 1984 Carrera, and ran across this excellent post from 2008, by user Inniswhe:

No weld to tunnel seat lowering

I'd like to reproduce what he did. I haven't measured the thickness of my current seat rail supports, and he unfortunately didn't mention what gauge metal he used to fabricate the new brackets - does anyone have any thoughts or suggestions? Thanks for any help.

Roger

Tom '74 911 · 10-11-2022, 08:10 AM

I am a big fan of nutserts, they are a such a great solution in certain circumstances... Seat mounting however, is not one of those circumstances in my opinion. I would personally not be comfortable with that set up as I don't have faith that the nutserts would stay put when exposed to an extreme force (ie: a crash)... I could be wrong, but that's an area that I wouldn't personally experiment with...

Just one opinion of course! Sorry, I'm sure that's not what you wanted to hear!

ChrisHamilton · 10-11-2022, 10:03 AM

Judging from the pics, it's either 18 or 16 gauge. Depending on how much you weigh either would work. If you and the seat are heavier then 16 gauge would be a good choice. Datsun 240Z's only used 20 gauge(!) for the seat brackets. A lot of them failed over the years.

I agree with Tom as well. Nutserts would not be ideal IMO. Welding would be preferred.

Fab64 · Fab64's Garage

Thanks for the replies, guys. I weigh 190 lb., and I have 1984 (manual) Sport Seats.

You're right, Tom; that's not what I wanted to hear - LOL!! I understand what you guys are saying about the nutserts. However, consider these points:

- The member (Inniswhe) who devised this method is a mechanical engineer.
- The nutserts are not the only thing holding the inboard seat support in; the other side of it is welded to the tabs of the original seat support (hence to the floor). The nutserts are providing mostly shear strength.
- There are no nutserts on the outboard seat support; it is welded to the tub on both sides.
- In 1984, the seat belts were still attached to the tub, not to the seats (as in succeeding years). Therefore, the seat would not have to support my body weight in a crash (that would be against the seat belts).
- Lastly, if I was to get into an accident severe enough to rip out those nutserts and the welds, I think the broken seat support would be the least of my worries.