Designing LATCH anchors for early 911

RallyJon · 11-02-2005, 07:53 AM

I've been trying to figure out a way to make transporting my 5 month old a bit safer (minivan comments not welcome

) on those days when I'm driving the 911 and have to pick him up or drop him off.

For kids < 1 year old, a rear facing car seat is required. In a 911, it has to go in the front seat since there's no way one would fit in the back. No airbags of course, so it's fine in the front seat.

So the question is, how best to anchor the car seat to the front seat/car?

I'm been using the seat belt, but it doesn't work very well. I was annoyed to learn that my otherwise excellent PEParts inertia reel belts do not have the federally mandated ratcheting function. So I've been threading the shoulder belt through the seat and anchoring it with a knurled belt lock placed just behind the male latch (so the lap portion of the belt takes the load). It's difficult getting the belt tight enough, and I'm sure the belt lock isn't any good for the webbing.

What I'd like to do is fabricate a pair of LATCH anchors to use the latch clips on the car seat. For those of you without kids, all car seats now come with two short belts with clips on the end sized to clip onto a 6mm bar. All new cars come with 6mm loops in the seats to match.

To test, I bought a length of 1/4" steel bar and found that by wedging it behind the seat it fit the LATCH clips perfectly and held the car seat much more securely than the seat belt did. But that's a hack, and I'd like to make sure my final solution meets the federal LATCH requirements.

The standard is this: the metal bar/loops must be able to sustain a horizontal forward force of 1,190 lb. That doesn't seem like a lot of force for a seat designed to hold a 250 lb adult.

So, option 1: will the seat itself resist that much force? That is, can I anchor the bar/loops to the seat base?

Or I go to option 2: the seat brackets. I'm sure that 6 hardened screws holding the seat bracket to the body can resist an extra 1200 lb in shear.

darthracing · darthracing's Garage

See my solution here.

http://www.darthracing.com/911/

Shroth hardware kit has some nice connectors.

-Todd

RallyJon · 03-12-2006, 04:04 PM

I gave up on the idea for the front seats, since my son's first birthday is this spring and it'll be legal to do forward-facing. I plan on installing the lower latch anchors in the passenger rear seat as shown in this thread:

not another kids seat in the carrera post

Those Shroth rings look good.

So the next quest is finding a small framed convertible seat that will fit tightly in the rear seat area.

darthracing · darthracing's Garage

Yeah. The Shroth connectors are a lot less $$ and less destructive than using actual 911 belt parts - though I have spares now, I did destroy 1 to get the hardware, and its not nearly as nice of a LATCH connecting experience as these Shroth rings are.

There is space to put both the belt and an adapter on the outboard seatbelt bolts.
Unfortunately, I have stripped my INBOARD 17mm bolts - I can't remove them without some serious destructive means now, so I like the idea of utilizing the belts for at least the lower part of the seats - or go outboard to outboard

The real trick is the seat itself - they seem to be getting BIGGER everytime I shop for new ones. Let us know if you find anything killer out there.

-Todd

jpnovak · 03-13-2006, 06:16 AM

I think something like this attached to the rear seatbelt mounting posts would be perfect. I want to mount these on my older daily driver that does not have LATCH. I hate the way the stock rear 3 pt belts try to tilt the car seat.

http://www.ogracing.com/eshop/itemdetail.asp?ses=109x1jjcv84psr1sb2&itemid=97&showbrake=1

RallyJon · 03-13-2006, 06:27 AM

Nice, but $64.95?!?! Porsche tax I guess...

jpnovak · 03-13-2006, 06:29 AM

I am sure there could be a cheaper source. I assume you could easily fab something with 1/4" angle iron and a drill.

RallyJon · 03-13-2006, 06:39 AM

I guess it depend on which type of Latch clip the car seat has. Better seats like the Roundabout have a 90° offset clip with a seatbelt style release. Cheaper seats use a clip which is in-line with the strap:

(from the other thread)

It probably makes sense to match the axis of the mount to the orientation of the clip/strap, so you're not twisting the strap.