How NOT to install seat belts...

[HarleyR]

Im sure most of you will agree , seeing something like this http://www.pbnation.com/showthread.php?t=2791488

[6'9"Witha69]

2 words: natural selection.

[MrQuick]

really? well considering this passes at FIA and NHRA sponsored races id say it would have to be somewhat safe. And the harnesses are mounted excatly how takata says you mount them.. takata knows a thing or two if you ask me.


what else besides my belts would cause me to die a horrible death?

proof that FIA and NHRA hate silly ricers! LOL j/k

[GBodyGMachine]

I know thats wrong, but the belts in my car go to the seat belt bolts that were originally for the rear seat belts. I think its a 60 degree angle.

[jerome]

how are those different than these:

http://www.schrothracing.com/product...ick-fit/qf-bmw

To everyone else jumping on the "that's a deathtrap!!!" bandwagon, please explain what is bad about that harness. It looks like the harnesses are attached to the OEM rear seatbelt mounting points.

Here is a quote from the Schroth website:

Shoulder belts must run from the shoulders horizontally or down, at no more than a 20° angle.

In cases where the shoulder belts must be routed down to the chassis floor, support by a roll cage bar or harness guide at the appropriate height is essential to establish the horizontal shoulder strap routing off the shoulder/HANS®. Most racing seats are not designed and tested to carry shoulder belt crash loads from downward installation. Severe injury or death could result. A 45° downward shoulder belt installation is possible with seats that SCHROTH has positively tested to take a load measured during a 50 kph [31 mph] and 28 G impact with a 75 kg (175 lb) dummy. Refer to the list of SCHROTH approved racing seats in section “Bolts, Seats and Stuff”. WARNING: 45° downward shoulder belt installation must never be used with HANS®.

What I take from that:
mounting shoulder belt at greater than 20 degrees from horizontal will create a downward force at the seat openings upon impact. All seats can take the force when at 20 degrees. When you get to an angle lower than that, you need a strong seat to withstand the downward force (so it doesn't crush the seat and subsequently your shoulders). Now if the dude used a high quality seat, he's fine, even if the harness is mounted lower than 20 degrees.

Jerome

[James OLC]

With all due respect Jerome, I think that you need to reread Schroth's statement... and think about where in this equation your body is... and think about things like speed.

Rose colored glasses don't really have a place when discussing harnesses and safety in racing applications (IMHO)

[Damn True]

Jerome,

You will find no such caveat in the data from Simpson & IMPACT!

[6'9"Witha69]

Especially true when a guy like me with a taller torso whose shoulders are above the harness slots. There is no room for excessive downward angle regardless of seat specs. And for anyone else who may be a little more rotund than most, remember that in an accident it is physics dictating where things go, and that object in motion will remain until acted on by an equal or greater force means there needs to be more sureity in the seat and harness for guys like me in the 250+ range vs 165ish.

After the accident my family was in on Saturday, there is no question in my mind about proper belt position. The best $280 I ever spent was thrown away after the accident. The Britax seat my 3 y/o was in kept her in PERFECT condition. The booster my 8 y/o was in kept her in the right position for the belt to do it's job. My wife and I also had our belts perfectly positioned. I know this is stock seatbelts compared to the discussion, but still relevant in terms of belt position.

And to be clear, after any major accident your child's car seat needs to be replaced. Most insurance companies take care of replacing them immediately aside from the rest of the claim.

[gordonquixote]

All I have is lap belts - FTW! lol

[James OLC]

All I have is lap belts - FTW! lol

And you are safer than if you had a 6-point harness mounted improperly.

[Declawed69]

I feel like this is hijacking the thread but what effect will raising the harness bar up a little to about back of head level have in the event of an accident? Does it also have some negative impact like having the bar to low?

[jerome]

With the angle too big, you have a large fraction of the tension in the belt (during impact) pulling downward and not straight back to keep you in the seat. This can cause the seat to buckle and then your shoulders will buckle next, messing up your spine.

That is, if your seat holes for shoulder harnesses are above your shoulders. If you are a big mofo and they are below, then all the force of the belt downwards will pull down on your shoulders. If the belt is horizontal, then there will be no downward pull.

What I was questioning above was why a high quality seat could not be expected to withstand these forces. Obviously it is best to have the belts mounted horizontal, and I would never myself mount them otherwise. However, I think with a good seat, you could get away with mounting the belts slightly lower than is recommended. Seeing a manufacturer that seems reputable and produces a presumably well-engineered product do the same thing makes me doubt that it is a bad as people make it out to be. The calculations will vary depending on what you assume the speed of impact, mass of occupant, angle of harness, and most importantly duration of impact (or how padded the collision is). Again, I agree safety should be anybody's top concern, and I would always mount belts at horizontal to be safe.

[Steve Chryssos]

Length is an issue as well. Belts are rated in stretch per inch . More length means more stretch.

[jason@gmachine]

Your harness should be mounted 1" to 1.5" below your shoulder line and 3" to 4" behind the seat.

The harness pictured above is very unsafe. I would never let anyone ride or drive that car.


jason

[Young Gun]

pfft, the guys on nation are a bunch of punks...all they do is e-thug and talk crap...i used to be on that site when I played paintball, its just funny to see how stupid some of them are...

[James OLC]

Your harness should be mounted 1" to 1.5" below your shoulder line and 3" to 4" behind the seat.

The harness pictured above is very unsafe. I would never let anyone ride or drive that car.


jason

lol... irony.

I all fairness though we all learn from our mistakes and it's good to help others so that they don't repeat those same mistakes.

[chicane67]

Isnt that the truth James...

As I see it:

[Tig Man]

What improper mounted belts did to Dale Earnhardt?

[Damn True]

Earnhardt died as a result of a basal skull fracture. As did Kenny Irwin and Adam Petty (both at loudon in the same year). While improper installation of Earnhardt's belts were contributing factors it had more to do with a lack of a device like a Hans than the belts.

[Tig Man]

Tore into from the impact. The adjuster was sideways and sheared the belt like you had cut it with a knife. The lap belts were mounted behind the seat, wrapped around the seat ! Or so that is what the inspectors told all of the teams after it happened. If you watch the wreck video in slow motion, you can see him going forward hitting the left side of the dash causing the fatal injuries.

Mark