My new harness bar

What are you going to be using the harness bar for? The proper use of a harness bar is to position the harnesses at the proper angle as they pass over your shoulders. You don't actually attach the harnesses to the bar, they typically attach to the body of the car at a point somewhere behind the harness bar. Attaching harnesses to the bar in the picture would not be safe.

Brey Krauss make a harness truss that you can attach the harnesses directly to, but its the only one I have ever seen and it is engineered very differently.

You mention that you don't race, but do you track the car at all? If you do, I would highly recommend that you do not attach harnesses to that bar. If you don't, why do you want harnesses at all? Even in a street accident, that bar does not look safe.

 

If racing 4 or 6 point belts are attached to the bar, there will be considerable bending moment on the bar. One inch diameter CrMo tubing sure does not seem adequate. It's probably wise to consult your belt supplier on this.

 

I doubt the (OEM) securing bolts would shear from an impact but it is likely the bar would bend, and without more information it does seem hard to speculate if the bar would break or tear from the G forces involved in an impact. I bought a harness bar some years ago from Peter Sweeney. The thing is very heavy duty with hardware to match. I think the advice given on talking to a fabricator makes sense.
Philip

 

Hello.

with the given dimensions I just did a quick check - I'm a mechanical engineer and calculate such things each day.
The result is, that this thing will bend or crack on an medium impact ( say 30 - 40 km/h or 20 - 25 mls/hr with a person weighing 70 kg ) like a match between your fingers.
Increasing the dimensions won't be a solution. The huge moments acting on the bar in case of an impact are way too big for this design.

Best Regards from Germany

Martin

 

http://www.pelicanparts.com/techarticles/911_harness_install/911_harness_install2.htm

 

Never !

.... and take notice of the introduction in red letters

 

Don't feel bad...my 308 had the same type of install albeit with a much much "beefier" bar...I don't race so I never used it and it never seemed safe to me and I had it removed and besides, the harness itself "expired" (even though still like new in the box) yes, be very careful, whether you use them or not harnesses do have a "expiration" period on them... in a ferrari (or any car) the seat belt is not only a safety device, it is likley the ONLY thing that will save your (and your passenger) life! On track days I see street ferraris and street drivers hit each other and hit walls all too often....I'd wear full Nomex along with the required helmet and have a roll bar and professional harness --- I am shocked at how poor the emergency rescue medical capabiliites of many of these tracks. Not like they have a helicopter standing by to whisk you to a trauma center like at F1 or Nascar!

 

DO NOT FOLLOW THESE INSTALL INSTRUcTIONS!!

There are two types of products, one is a HARNESS BAR and the other in a HARNESS MOUNT/TRUSS. In this picture, the harnesses were mounted to a harness bar, something the manufacturer never intened. Here is the manufacturer's website, notice the two different products with two different purposes:

http://www.bkauto.com/porsche/harness.php

 

as a foot note , I've just installed a 4 point Sabelt Clubman system and
in the instructions accompanying the belts , it does not mention any
form of 'harness bar' attachment for the shoulder belts. The
illustrations all document solid mounts onto the chassis (shown usually
using the existing belt anchor points).

as for the "harness bar" system , I have no idea. Has anyone any
facts/data/manufacturer's warnings concerning the faults (if any) with
this system ?

not trying to be a smart-ass , but would like to learn more.

cheers.