DDK - Die Deutschen Klassiker

This is what you need.

That looks better John,

this is what I used, nothing special...



Chris

PLEASE do not be offended, this is a great original car, but are you sure about those seat belt mounts for the lap straps?
I can't help but feel they will ride-up the seat/your stomach and chest in a hard frontal and you will submarine under the belt?

I say this because I doubt you will find a factory car with those locations.
The straps usually do down not back from the pelvic area.

Again, trying to help, nothing else.

911hillclimber wrote:PLEASE do not be offended, this is a great original car, but are you sure about those seat belt mounts for the lap straps?
I can't help but feel they will ride-up the seat/your stomach and chest in a hard frontal and you will submarine under the belt?

Chris, i have to agree (but maybe that was just a mockup?). This page of the Schroth website might be useful. It says lap straps should run down from your lap at approx 60 degrees from horizontal:
http://www.schroth.com/installation-ins ... etries.htm

I'm no expert in the ways for harnesses but even to my untrained eyes the location does look wrong.

911hillclimber wrote:PLEASE do not be offended, this is a great original car, but are you sure about those seat belt mounts for the lap straps?
I can't help but feel they will ride-up the seat/your stomach and chest in a hard frontal and you will submarine under the belt?

I say this because I doubt you will find a factory car with those locations.
The straps usually do down not back from the pelvic area.

Again, trying to help, nothing else.

Not offended in the slightest ! Much appreciated guys !! I am the first to listen to people who are more knowledgeable than me on these matters, especially when it comes to safety.

So I have had another look and I have to agree, those lap belts should be angled down.

So what are the options :

- Bolt through the floor ?
- Attach to the seat frame ?

Any advice and photos would be greatly appreciated.


Cheers
Chris

On my 73T hillclimb car I have full 4 point racing harness. It is a RHD car.
The left hand lap strap is bolted to the transmission tunnel just ahead of the hole for the gear linkage at the back of the car. The fastening is through the tunnel sheet metal and the 'nut' is a 6mm thick plate , about 30 x 40mm size to spread the load on 'pull/impact which is inside the tunnel and within reach through the gear linkage hole.

The strap is hooked through the forged steel eyelet which you already have which is screwed into the plate (that also came with the 4 point harness).

The right hand lap strap is hooked to a similar set-up which is bolted through the seat runner (that Porsche welded to the shell) rear of the seat mounted position.

It must not be bolted to the seat fixing/frame/ adjusting runner, nothing must be.

The two over-the-shoulder straps run over the shoulder and down to the two fixings for the rear lap belts. What you have is perfect.

For 15 years this set-up passed MoT's and event scrutineers.

I can photograph this lot late tomorrow once I'm back from my hillclimb race!

My car has an FIA race seat which makes this a lot easier than having a road seat (no seat back to break to gain rear access). For racing you have to block the ability for the seat back to be adjusted.

Just done a rough sketch from memory:

Just thrown a rough sketch together!

Out of interest why do we all use such huge fastenings for belts. I would be interested to know the force that would be required to pull a 9/16 or 14 mm thread out of a 6 mm thick plate over a surface area 1200mm2... bet its more than a body could sustain. I only ask since my dads plane and others I've seen commonly use 6mm bolts into pretty flimsy panels the argument being that the outright bolt strength is sufficient and deformation of the panel for mounting actually serves to absorb rather than transmit an impact force.

Definitely good to get it all in the right places to prevent "submarining" and loading the seat shell though.

Andy:
The parts that come with the 4 point/6 point harnesses for motorsport all come with these 'plate-nuts' and eyebolts, so we all use them.
They are very over-engineered I would agree.

Yes, the sketch is a bit rough-arsed but it was late in the day!
However it shows what I did and my 911 has had one 'test'of the security already on a hillclimb, so I've practised what I preach!

I might temp an argument here, but a real race seat works well with a 4 point, but a road seat I think compromises them.
The race seat has guide apertures to thread the belts through so controlling their angles of fastening and cover of the body.

After a weekend racing my Lola, the 6 point harness can seriously squash your Crown Jewels!
Don't fit/use them in a road car.

Nige was being sarky - it's a cool, neat and impressive looking sketch


Sent from my iPad using Tapatalk HD

Yup, just a compliment hidden in sarcasm. You know me better.

Nige wrote:I'm no expert in the ways for harnesses but even to my untrained eyes the location does look wrong.

Not what I'd heard Nige

But on topic, go with the Schroth recommendations.

No negative taken!

The belt angles are important to stop any crushing of internal parts of the body. DDK'ers have a responsibility to question things we see!
We are all too valuable to lose!!!

Thanks guys, all great info...

Next point of debate.....Single windscreen wiper linkages, without being able to find any info on what the DTM and Carrera cup guys use.....I decided to make my own





and it works a treat


Chris