Seat Harness mounting, following on from 'Race Seats!' thread.. Options

[raz128]

Anyone want to clear this up for me?
I've got a 4point harness on my driver seat and a 3point harness on my passenger seat
When I bought the 3-point harness. The instruction booklet said to mount the tail strap of the harness between 0-45 degrees paralell to the ground which i did on the passenger side.
After doing some research to see if i could confirm it, the Schroth harnesses said the same thing

However i did come across this:
http://www.gforce.com/pdf/harnessinstall.pdf
for those too lazy to read it (or cant run pdf files) it says it's best to mount the tail strap -5 to +30degrees from a horizontal line to shoulder height.

Which is best mount to use? The lower point under the original rear seats or on the C-pillar?
The mounting point on the C-pillar would be within -5 to +30degrees that the pdf file states. but does it satisfy the 0 to +45degree instructions by OMP and Scroth?





This post has been edited by raz128: Jan 30, 2007 - 10:18 AM

[playr158]

Actually its 0 - 45 degrees. I've got my harness setup like the passenger side of the first pic (the three point). The danger comes when people bolt their harnessess to the floor...near the seat brackets. Raz's look fine...all the places he's bolted them up to are quite safe.

how do you feel knowing you are now in the hospital knowing you're a paraplegic.
and contributing to other peoples potentially life threatening situation?
please don't give any more advice since you are very wrong.

http://www.sparcousa.com/resourceFiles/16.pdf

Proper Installation is Important
The effectiveness of a restraint assembly is also influenced by attachment techniques. The principal precaution for installing the mounting hardware to the vehicle is to minimize bending stress in the fitting. This is achieved by making sure the belts pull from a straight angle against the hardware. The assembly should be installed so that the straps do not rub against any surface that can cause the webbing to fray. The anchoring mechanisms should also periodically be checked so that they don't become loose or weakened.
Proper installation of the restraint assembly also means achieving the correct fit to the driver. Belts should be as short as possible to reduce stretching for better control of occupant movement.
The attachment points must provide the optimum geometry to minimize movement of the belts. Lap belts perform best when they act at an angle between 45° and 55° relative to the longitudinal axis of the vehicle as illustrated in part A of the Figure. This angle permits the lap belt to react to the upward pull of the shoulder harness. A system installed with a shallow belt angle, as shown in part B of the Figure, permits the shoulder harness to pull the lap belt up off the pelvic area and into the abdominal region with the likelihood of injury to internal organs.
The end attachments of the shoulder harness must also be installed at appropriate angles. The ideal position is anywhere between 5° below and 30° above the driver's shoulder, as seen in part C of the Figure.
If the upper attachment point falls significantly below the driver's shoulder, then a spinal compression injury is likely to occur. In an accident situation, the shoulder belts pull down and back on the torso as they resist the forward motion of the driver. The resultant restraint force compresses the spinal column and will add to the stresses in the spine already caused by the force of the crash impact.
On the other hand, if the trailing ends of the harness are too far above the shoulder (greater than 30°), then two problems can occur. First, tension in the shoulder harness is increased and undue stress is applied to the harness and its structural attachments. Second, excessive angle will
cause excessive motion. If the harness belts are too far above the shoulder, they will provide little resistance to forward motion of the driver's upper torso. The result is impact with the steering wheel and the possibility of neck injury. The shoulder straps should also be 3-6" apart behind the driver's neck to prevent slippage off the shoulders.
The reliability of a restraint system is greatly affected by the way it is installed. It is imperative to follow the installation instructions provided by the seat belt manufacturer. Also, the necessity of replacing or rewebbing seat belts every two years cannot be more important.
As cars become more advanced and consequently go faster, everything possible must be done to make the racing experience safe as well as fun. Failure to do so can cause serious injury, or worse. If there is anything that can be learned from the sport of racing, it's that anything is possible, and taking the attitude that "it won't happen to me" is risky, because it does happen.

also please remember to replace your harnesses EVERY 2 years!

also make sure you have SFI certified seats and your equipment is CERTIFIED.
Common seats found are NOT certified and will break under less then 1/2 the force and sometimes 1/4 the force that a certified seat will withstand.

This post has been edited by playr158: Jan 30, 2007 - 12:31 PM