Seat belt anchorage points.

Donunder · #1 (**permalink**) 11-20-2010, 04:36 PM

The Arntz that 750HP has been inquiring about finally arrives in Brisbane (Australia) this week.

To compliance the car for Australian registration certain modifications have to be made, such as new headlights that dip to the left, a reversing light activated by a gearbox switch, and possibly a high level brake light, etc -- all pretty straight-forward and understandable stuff.

What is a bit hard to take however is that the car's lovely 3" wide racing harness has to be ditched in favour of a retractable lap-sash seatbelt system. This will necessitate a floor mounting for the lap part of the belt either side of the seats with the tongue-clip on the outer or door side of the seats and the fixed mount adjacent to the transmission tunnel. The inner upper mountings, the shoulder sash part, are to be located at shoulder height between the seats. The retractor mechanism can either be mounted at this point, or the belt can pass through a runner and the retractor mechanism can then be affixed to the floor.

With the fuel tank being mounted up high behind the seats, how have other Arntz owners tackled this installation? Is there a substantial frame mount available up high on which to mount the retractor or, because of the fuel tank's proximity, is it preferable to mount it on the floor? At 6'5" I'm planning on using ALL available space behind the seat (and then some!) to be able to fit into the car, so I guess I'm really hoping that the bulky space-consuming retractor roller can be located up high between the seats.

Any information, and if possible some photos, on lap-sash belt installations, particularly those with high mounted fuel tanks and high mounted belt retractors, would be very much appreciated.

750hp · #2 (**permalink**) 11-21-2010, 03:24 AM

To explain things, Don's my father and this is his car. I love being able to share a passion/hobby with my old man...

I finally found a couple of photos of an Arntz chassis, but it doesn't seem to show any framework / support structure directly behind the seats.

Here's where the fuel cell is currently mounted:

Seems as though the harness is mounted down low behind the seats, which further makes me think that some engineering will be required. The fuel cell might have to be relocated...

If anyone has mounted retractable belts, that's exactly what we're interested in. Further to that, if anyone has mounted harnesses with the shoulder straps anchored higher than the above photo, where did you mount them to?

Thanks for any assistance or advice.

Outwest34au · #3 (**permalink**) 11-21-2010, 02:10 PM

Nice one Don and Craig, good to see the plan came off for you.
I wasn't sure if I was able to use the standard seatbelt mounting points on mine (not an Arntz of course) so I added a rear central mount point early in the piece. Some thick as angle, some 2 x 2 x 5/16 RHS and some 1/2" plate at the top.
The standard mounts are pieces of 40mm x 40 mm rhs welded to the side of the rails with some flat plate capping the top, the hole 7/16 is then tapped in for the bolts.
View a few ideas and I'm sure you will find what's easiest and best in your case.
Cheers

joyridin' · #4 (**permalink**) 11-25-2010, 12:38 AM

WOW..my Arntz looks nothing like this in the trunk. Mine has the tank mounted in the bottom of the trunk and there is a killer hoop right behind the seat. You could easily mount a retractable seatbelt there with a few mods. Mine has a space between the back of the trunk and behind the seats. In that space is a hoop or support bar about 1.5 - 1.75" in diameter. I would assume your car has it, but with the tank located there, I'm not sure. It might be behind the tank..maybe that is the mounting for the tank?

750hp · #5 (**permalink**) 11-25-2010, 12:58 AM

Outwest - Cheers. Seeing pics like yours certainly makes it easier for me to visual some options. I'm hoping it can be a bolt-in deal, as welding a support structure into a completed car could be a pain.

Joyridin' - Thanks heaps for the information. To get it right in my head - is there a space between the interior and the trunk that's exposed to the elements and is visible when looking from underneath the car? ie: Is there a glass panel behind the seats, then a void/space, than a separate glass panel as the backing panel in the trunk? If so, does the hoop / support bar run within that void? Going by the Arntz chassis in the first pic, am I correct in assuming that it must be bolted in and not welded? Does it run the full width of the car, or just on the horizontal section of the chassis between the wheels?

Got any pics of this area of your car by any chance?

Thanks again,

Craig

spookypt · #6 (**permalink**) 11-25-2010, 02:38 AM

Nothing ole ozvenom can't fix I'm sure. Welcome to the left hooker club don. Love your new ride and finally realizing the dream. Soak it up Craig what u and ya old man have us pretty special. Your lefty friend team overdraft racing!

Donunder · #7 (**permalink**) 11-25-2010, 04:52 AM

Thanks for the welcome Spook.

We collected her from the importer's today and she's now in the tender care of Oz for compliancing and some fancy internal s t r e t c h i n g work to try to get me to fit in. I'm absolutely rapt in the way she looks. You'd never pick her for a thirty year old car. The photos looked good but to finally actually see her in the flesh gave me goosebumps.

Scott took me for a ride around the car park. (He's the only one who can drive it at the moment.

) It rides a treat and that ole big block sounds fantastic -- nice deep rumble from the side-pipes, not too loud.

Cross fingers we'll have it at Hope Is in a couple of weeks for brekky!

joyridin' · #8 (**permalink**) 11-25-2010, 06:05 AM

In my car, the situation you describe is correct. I am not sure if somebody modified it, or it was this way from the factory. When you look at the trunk, mu tank sits on the bottom. There is a wall where your tank sits. It is made of wood and seems to be that way from the factory. It has 2 removable panels that are carpeted. If you remove these panels, there is a large hoop which would be located right behind the seats. It is basically open to the elements.

When you go from the interior, there is a panel behind the seats, which I assume is fberglass. The roll bar somehow mounts in that void. I haven't really looked at it in a while. I can grab some pcs, but not until late next week. The hoop is bolted to the frame. I am not sure if the roll bar mounts to this hoop or the frame.

In my Arntz, it would be relatively easy to make the mounting points as you describe.

750hp · #9 (**permalink**) 11-25-2010, 06:22 AM

Glad to hear that the Arntz has that structure in place. No need to take pics especially if you don't have some on your computer already, thanks all the same. As Don mentioned, the car cleared Australian customs today, so the fun's about to begin. Once the car is up on a hoist tomorrow, I'm sure a lot more will be revealed.

Spook - bloody rapt with how it looks! Can't wait to see what Scotty pulls out of his bag o tricks to find another 12" of legroom in there...! Keen to see under it too. Super keen to see it finished and on the road because that means (1) Dad finally has the Cobra that he's waited SOOOOO long for, and (2) Scott then has space in his workshop to put some finishing touches on the Chevelle