6pt harness install eyelet bolt location

[dre99gsx]

Anyone have any tips on installing the eyelet bolts in the z4 for a 6pt harness? Photos would help.

[Vanne]

that would all depend on what you have inside your car?

if you have a rollcage, the shoulder straps wrap around the rear STB. The Seat mounts should have anchors for the lap belt and the center (between) the legs either go through the bottom of the floor pan, or onto a sub section made for the seat mount.

There are lots of varying versions of this. just pay attention to the angle of the shoulder belts.

If you have no cage, then there are other ways guys have done it.

[dre99gsx]

I have a Weichers bolt-in cage, but my impression is that I need to drill 3 holes for three eyebolts. Looking for ideas on locations where some folks . I would prefer to use existing anchors where possible for the bottom belt mounts, but it seems that the center mount must be drilled through the floor pan?

[sikedsyko]

My cage builder built a bar that extends between the seat mounts that I could wrap the sub-straps around so I didn't have to add a mount point to the chassis for the sub straps.

[dre99gsx]

Is that considered safe based on regulations? I need something that won't fail inspection.

[Michael9218]

It would help if you would describe your interior setup. Do you have a fixed back race seat or stock seats? If race seats, how do you have them mounted?

Typically, shoulder belts are looped around a horizontal harness bar (do not drill holes in this bar!). Laps should be mounted with weld in plates on the structural side sills. Subs take less load (they really only prevent the lap from riding above your pelvic bone in an impact) and can be mounted with backing plates through the thin floor sheet metal. If you have VAC style aluminum seat mounts, Schroth makes a clip that can be mounted to the seat mounts.

https://www.schroth.com/en/segments/.../b-23-kit.html

As for passing tech, read your rule book!

[dre99gsx]

I get the regulations and such, just looking to see where guys mount these on the floor (lap and sub ends). Are you guys drilling the trans tunnel to feed an eyelet with a backing plate or using the OEM belt mount? (any pics of where you installed the eyelet?) I have standard floor mounts and an OMP HTE seat.

I'm seeing that I have to mount the subs directly to the floor (drilling holes), but the Z4 has a bunch of wiring and fuel lines running directly underneath it.

[Vanne]

How did you mount your omp seat to the floor using the OEM floor mounts?
I can take a pic of my seat mounts if that helps?



This is my pax side one. The mount circled in orange is the lap belt. The cross bar is made from high tensile steel, even though it doesn't have to take much of a load. Again. Wondering how you've mounted your chair without mounts on the OEM holes?

[Michael9218]

The seat mount Vanne has pictured is the type I meant when I said a VAC type mount. Billet aluminum with a bunch of threaded holes. These are surprisingly strong.

The sub mount bar Vanne pictured would work well. Or simply bolt those Schroth clips. Either would be sufficient.

For the laps, in a Z3MR I once had, I bolted a piece of 3/16” cold rolled steel under the mount at the back of the VAC mount. It was bent 90 degrees with a hole for the belt clip (you really don’t need the threaded eye at that point). I crash tested it at Road Atlanta at over 100 mph. Held up fine. 👍 😬

Personally, I prefer to have the lap mounts welded to the chassis. Those factory seat mounts are only spot welded to the floor...

[dre99gsx]

I have the seat mounted directly to the chassis (no sliders) using the Brey Krause mounts:

similar to these https://www.bkauto.com/R_9075_Side_M...o_p/r-9075.htm

Which is funny, looks like they even make a sub mount:

https://www.bkauto.com/R_9032_Sub_St...t_p/r-9032.htm

[dre99gsx]

Ok. I should have researched but seems I already have the solution - no drilling for eye bolts needed. Since I run the Brey Krause seat mounts, it has everything that I didn't realize until I looked lol