Harness bar install

[SUKXOST]

Installed my harness bar today as well: (seats and harnesses will be installed next week or two...or three)

[mp51998]

I just got the harness install done and written up. I had to leave to get my daughter. I'll post up when I get home in about an hour. Just in time for the weekend.

[SUKXOST]

let me know how solid yours is....think I need to extend the angled bars and push the main bar back further.....mine has a lil play in it with everything as tight as they will go....AND its in the way of my seatbelt and it won't self-retract...gotta fix that.

[mp51998]

First post updated.
Sux, my bar moves around a little and blocks my seat belt. It will retract if I hand feed it. I believe it will never be super tight. The purpose is to keep the belt up and keep it from crushing you in case of impact. If we attached the harness directly to the floor behind the seat it would cause the belt and seat to compress down and cause injury. I think, and could be wrong, in case of collision the bar will resist the downaward force and keep the harness in position to stop forward movement.

[SUKXOST]

MAN that harness install looks uber involved. John told me NOTHING was required to do it....I dunno, maybe I asked the wrong question.

[mp51998]

I wish the factory seat could accommodate the five point harness. When I would really crank down on the shoulder straps, the lap belt will ride up a little. I'd like it to stay on my waist more. It's not bad. Maybe an inch or so.

[jksynergy]

mp, thanks. I had to subscribe to this as our car will not be in until maybe April. Great write up and pics!

[Synner]

Seems to be a lot of misconceptions.
The place you attach your harnesses to should never move upon impact or jiggle when touched. The webbing on the belts is intended to stretch to reduce load while keeping you in place. By having the mounting point move you create a significant shear load on a bolt that in this bar is in single shear. What grade and material are the bolts and end links made of on these bars? What is the tubing size, wall thickness, and material of the bars? A mounting point that moves is unsafe and will drastically reduce the shock load the harness will be able to deal with.

If a seat collapses under the strain of a crash while using a harness then the seat is not meant for motorsports. Choosing a weaker mount or harness to overcome another weak point will result in death/injury at very low speeds that you would have walked away from with your 3-point belt. Hopefully all the 4-points chosen were antisubmarine or they won't pass tech and are much less safe than your stock belt configuration.

A lot goes into planning a safety device intended to save your life at motorsports speeds. I didn't see any of the questions I raised above asked and answered in the sale thread other than the fact that it hadn't been tested for any type of crash or safety load certification. I'm not an expert on the subject but have been doing a lot of research, and have a solid knowledge of structural engineering, before I buy or build something for my own car. There is a lot of stuff out there that is less safe and goes through little to no safety testing before being sold. Do some research as these things are the safety devices intended to save your life in a crash.

[mp51998]

Originally Posted by Synner

Seems to be a lot of misconceptions.
The place you attach your harnesses to should never move upon impact or jiggle when touched. The webbing on the belts is intended to stretch to reduce load while keeping you in place. By having the mounting point move you create a significant shear load on a bolt that in this bar is in single shear. What grade and material are the bolts and end links made of on these bars? What is the tubing size, wall thickness, and material of the bars? A mounting point that moves is unsafe and will drastically reduce the shock load the harness will be able to deal with.

If a seat collapses under the strain of a crash while using a harness then the seat is not meant for motorsports. Choosing a weaker mount or harness to overcome another weak point will result in death/injury at very low speeds that you would have walked away from with your 3-point belt. Hopefully all the 4-points chosen were antisubmarine or they won't pass tech and are much less safe than your stock belt configuration.

A lot goes into planning a safety device intended to save your life at motorsports speeds. I didn't see any of the questions I raised above asked and answered in the sale thread other than the fact that it hadn't been tested for any type of crash or safety load certification. I'm not an expert on the subject but have been doing a lot of research, and have a solid knowledge of structural engineering, before I buy or build something for my own car. There is a lot of stuff out there that is less safe and goes through little to no safety testing before being sold. Do some research as these things are the safety devices intended to save your life in a crash.

Very valid points Synner that I do not have answers for. I do not want this to sound defensive so please do not read it that way. I am not a structural engineer or a professional of any kind.
I can tell you that the mounting points for the actual harness is stationary and does not move whatsoever. They are all the same mounting points as the OEM belts. I did reuse all OEM bolts with the exception of two. They are both Grade 8 which are the best I could get. I do not know what the shear rating is for these two bolts. The only movement is with the harness bar. Based on your observations I will adjust it to make sure it has no movement.
When I was referring to the seat possibly collapsing, I was referring to some information I read in another thread were someone was asking if it was ok to mount the shoulder straps to the rear seat mounts. He was told that the belt would pull down, forcing the seat back to collapse and cause injury. Again I am using the stock seats with a four point harness. No submarine hole in seat and no submarine strap on harness.
You have peaked my interest in the manufacturing of the harness bar itself. I do not know the thickness of the tubing used nor the rating for the heim joints. There are no manufacturer markings on the bar, harness or the box they came in. I will contact the seller and see if I can find manufacturer contact info and inquire with them directly.
So based on your experience and and research, as long as the harness is mounted in the locations indicated and the harness bar is solid, no movement at all, we should be okay?

Here is the web site I did research showing mounting points for different configurations and where they say it is okay to bend the D-links as long as it's not excessively

http://www.schroth.com/installation-...stallation.htm

I appreciate the constructive criticism.

[Synner]

Definitely didn't sound defensive and I only want people to consider that their life is now in the hands of a system with zero testing or R&D. I also see mods being done that don't meet any racing class safety standards. I've pissed away enough money doing things twice that maybe I can stop someone else from doing the same, from being turned away at an event, and serious injury at the tracks that don't take open track day safety inspections seriously.

A couple points:
1) Rear straps must be within 20 degrees of horizontal going away from your shoulder to be legal. The longer the straps the more flex you're allowing during a wreck thus the more you will move in the event of a wreck. Its to ensure you don't fly up from the seat as much as prevent excess pressure on the seat frame.

2) The thinner diameter the tubing the more likely to collapse under stress. As soon as the down tube collapses nothing holds the bar in place thus your harness is free to move and not hold you in place.

3) Merely using stock mounting points doesn't guarantee safety, it's a holistic approach as the weakest link shall be found. However I would never advise using a non-stock mounting point without bracing both the connection point as well as the complete panel. The right way to do it is tie it into the car's frame and/or roll cage.

4) There is only 1 4-point harness thats legal for motorsports and only a couple classes allow it at all, that is the Schroth with ASM. Even the classes that allow a 4 point highly recommend 5+ and a mandatory supplemental safety inspection is necessary to ensure any 4-point has ASM features. I would use the stock belts and deal with the side to side movement over a 4-point any day of the week. There's a reason why they're illegal in 90% of racing classes and the other 10% mandate a single type that only 1 company makes.

My car was seeing speeds in excess of 150mph with stock tires/engine and modified suspension. Honestly I should do a roll cage but desire a stealth look so I am compromising safety slightly as well. I like the BK Auto harness bar but hate the price, its the only one that did any load testing. I am looking at possibly welding my own that would use 1-3/4" primary and 1-5/8" down tubes with no rod ends whatsoever and a minimum 1/2" bolt size wherever I use one that isn't a stock seatbelt bolt. Wall thickness is .134 on the tubing. I would mimic the rear mounting point of the BK and welded cross braces since I can't bend tubing like they did.

I will be going with a 6-point since 5-point are rough on the nuts. The crotch belts will slide between the upper/lower seat cushions and mount on the rear seat bracket bolts. Originally I was considering modifying the stock seat for the strap but found "seat modifications" to be illegal in some classes although I fail to understand the logic behind it when placed properly. I assume its because they can't guarantee someone puts it in the right place therefore the submarine risk still exists.

The cost of hardware that meets the alloy and strength requirements that I would use in this application isn't cheap and thats why I didn't become a part of the group buy. There is no hardware specs, thin down tubes, and for the price I just don't see how they're using high end components for the price. Not to be a Debbie downer but if a company makes safety equipment and doesn't test it how do they know its safe? When the owner of the company trusts his life to it hitting a wall at triple digit speeds then sign me up. I don't see how I can make one for under $200 using high quality materials and my labor is free. Granted I don't get wholesale material costs but there would be a fair amount of welding/fabrication to build it strong.

[jksynergy]

Synner, in mp's case he only has the bar more as a guide for the belts vs a mounting point for them. Would not the stress of the belts be taken up by the seat vs the bar? If he's using the stock seatbelt mounting points then I would see the stress being on those points. Am I missing something here?


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[Synner]

As a guide its not as big of a deal but the minority of people mount it that way, most wrap it around the bar. The bar will still see a decent load, but not as much, when the belt gets loaded. The one risk I mentioned of mounting it this way is the longer the belt length the more stretch will happen in an accident.

He is also using a 4-point without ASM so they are much less safe than stock in the event of a collision.

[JOHNSONROD]

good topic and good respectful discussion.
ive went through the entire ordeal of wanting harnesses, looking at harness bars, reading all of the negative stuff about them, getting pissed because of all the dis-information. ive settled on the RPM cage, sparco fia legal seats and 3 inch 5 point harnesses. the deciding factor for me was reading the NASA forums and how they view harness bars and 4 point harnesses. the one question that made my mind up was... do you really want to put something in your car that holds your head 1 inch from the roof when your roof can collapse a foot in a roll over?
ive started to run in the fast classes and even instruct at some events. we are going to daytona, vir, sebring, the new corvette track and road atlanta in 2014. if you are doing autocross or wanting something for an occasional track event at a medium or short track, this setup would probably be fine. the stock seats with harnesses are another can of worms that ill leave up to everyone to decide on his own.
for the guys who havent spent the cash yet, another option that i was running in 2013 was the factory three point with a set of lap belts to keep you in the seat. this option is preferred over a harness bar, factory seat setup by most clubs.

here is one of the many talks about harnesses and harness bars.
http://www.nasaforums.com/viewtopic.php?f=1&t=107529

[jksynergy]

Originally Posted by JOHNSONROD

good topic and good respectful discussion.
ive went through the entire ordeal of wanting harnesses, looking at harness bars, reading all of the negative stuff about them, getting pissed because of all the dis-information. ive settled on the RPM cage, sparco fia legal seats and 3 inch 5 point harnesses. the deciding factor for me was reading the NASA forums and how they view harness bars and 4 point harnesses. the one question that made my mind up was... do you really want to put something in your car that holds your head 1 inch from the roof when your roof can collapse a foot in a roll over?
ive started to run in the fast classes and even instruct at some events. we are going to daytona, vir, sebring, the new corvette track and road atlanta in 2014. if you are doing autocross or wanting something for an occasional track event at a medium or short track, this setup would probably be fine. the stock seats with harnesses are another can of worms that ill leave up to everyone to decide on his own.
for the guys who havent spent the cash yet, another option that i was running in 2013 was the factory three point with a set of lap belts to keep you in the seat. this option is preferred over a harness bar, factory seat setup by most clubs.

here is one of the many talks about harnesses and harness bars.
http://www.nasaforums.com/viewtopic.php?f=1&t=107529

As one who will be autocrossing this year and maybe a track day at Gateway I appreciate the comment that it may be fine for autocrossing. If anything, I can always return the 4 points and save up for 6 points instead.


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