Moving 3.2 Carrera inboard seat belt receptacles from seat to tunnel or floor

[oly]

Does anybody have any ideas for this? I'm especially interested in seeing pictures of installations.

I want to move the original seat belt receptacles from the seat to the tunnel or the floor in my 3.2 Carrera. The reason is that I'm using a racing shell seat connected to the car mount points with brackets (no sliders). Since the seat belt receptacles mount to the original seat, I need a new mounting location for them.

So my goal is to transfer the seat belt load to the car body in a way that makes acceptable stresses along the whole load path. I also want the location to be at about the same fore / aft location as the outboard seat belt mounts. This rules out using the car mount points. These are the options that I can think of so far for mounting:

1. on tunnel using welded on doubler plates -
PRO excellent load transfer (same as on the SC),
CONs welding near the fuel lines inside the tunnel is dangerous

2. on tunnel using bolted on doubler plates -
PROs can do myself & doesn't require danger of welding,
CON will add hard metal pieces to the inside of the tunnel that could chafe on fuel lines

3. on floor using welded on doubler plates -
PRO excellent load transfer,
CONs have to retreat area for rust protection

4. on floor using bolted on doubler plates -
PRO can do myself,
CON holes in the tub

[don911]

I looked at this before and didn't find a good solution. I'm using brey krause seat belt anchors with my race seats. When you figure it out, please post.

[oly]

don911,

Are you using the BK R-9005 seatbelt mounts? Did you just bolt them on the aft most holes of the factory mounts?

[ChrisBennet]

I made a U shaped bracket similar to those in an pre-85? car with a backing plate that went inside the tunnel.
-Chrrs

[don911]

Originally Posted by oly

don911,

Are you using the BK R-9005 seatbelt mounts? Did you just bolt them on the aft most holes of the factory mounts?

Yes, R-9005. I tried it both ways. I'm using sliders so I have it mounted between the slider and the side mount same as it was with the factory seat.

Also, I have one factory anchor bracket from a non powered seat sitting in the garage if you want it. Here's a picture of my set up. I currently have an eye bolt installed for my harness.

[911pcars]

I think the factory seat receptacle floor bracket is U-shaped and welded to the tunnel.

Instead, I used a short length of trailer hitch square tubing. Drilled vertical holes to place a 1/2" thru- bolt into the floor. Back it up with a large diameter hardened (seat belt) washer and nut. Cross holes in the bracket attach the factory seat belt receptacles with a single bolt and lock nut. Use large dia. Nylon washers on either side of each receptacle so they can easily rotate around the bolt without flopping around.

Sherwood

[Jeff Alton]

Here I go to the garage to take a pic....................

Cheers

[Jeff Alton]

Okay, back from the garage.....

These are in my 84, and they are welded to the tunnel from the factory. I run eye bolts in them for the harness and the factory seatbelt receptacle.





Cheers

[jester911]

I don't have pics but I can take some if needed. I have seat brackets that have the seat belt brackets welded to them. They are Corbeau brackets and they come this way.

[oly]

Thanks for the posts everybody!

[oly]

ChrisBennet,

Can you post a picture of your U shaped bracket? I assume that it is inverted and that the vertical parts of the U bolt to the vertical parts of the tunnel. Is that right?

[oly]

don911,

I've got the same problem when I use R-9005s; they put the receptacle too high for the seat belt slot in the seat. My additional problem is that even in the most aft position on the car mount, the R-9005 is forward of the seat belt slot in the seat.

[oly]

911pcars ,

Your installation sounds like a good one. Would you mind posting a picture?

I assume that the "large diameter hardened (seat belt) washer" are more of a precison looking washer than the common stamp cut washers. Is that right? Where did you find the hardened washers? I've done some looking on the McMaster Carr website and the Grainger website but haven't seen anything other than what lookes like normal stamp cut washers with relatively big tolerance on their thickness.

[oly]

Jeff Alton,

That looks like a stout installation. How did you do the welding and not get the fuel lines too hot?

Also, what is the purpose of that rod running through both pictures?

[oly]

jester911,

Mounting the seatbelt to the seat bracket would be convenient. But I heard that some inspectors would not accept that load path for DE or racing. Have you had any issues with that?

[jester911]

No problems with DE. I don't do W2W with my car but I have done several DE's with the PCA without any problems.

[oly]

Everybody,

Has anyone ever seen or considered mounting the receptacles to a piece of metal that cantilevers off of the top inside of the seat mount brackets? Specifically, the seat mounts that are welded in the car, the car floor, and the car tunnel form a rectangular channel that runs fore/aft. The channel is about 1" wide and 3" high. The seat attaches to the top outside of that tunnel. It seems like I could bolt a long bar of metal on the top inside of the tunnel; one bolt at the front seat mount and one (or two) bolts at the aft seat mount. The bolted in bar could extend past the aft end of the seat mount channel and give a rigid mounting location of the seat belt receptacles. I like it because it would not require permanent tub changes like drilling or welding would.

[oly]

jester911,

Okay, thanks!

[ChrisBennet]

Originally Posted by oly

ChrisBennet,

Can you post a picture of your U shaped bracket? I assume that it is inverted and that the vertical parts of the U bolt to the vertical parts of the tunnel. Is that right?

I think the offset holes for the belts is key. This allows them to belts to swivel.
The crappy welding of the nuts on the backing plate is the my first (and only) attempt at welding.
With this arrangement, I had my factory seat belts and racing harnesses lap belts attached to the same bracker. A lock nut kept things from loosening.
-Chris

[jester911]

Art, what you describe is not much different from the Corbeau seat bracket.
Do you have a roll bar or cage?