Harness Bar

[fastbmw7]

How about adding a horizontal bar spanning the width between your roll bar vertical uprights? You could then attach the shoulder belts to the crossbar and dramatically shorten their length which is better, (meaning less stretch).

[frankiman]

this is what i was thinking of fabricating for my car

basically it's a ''driver side only harness/roll over bar''

since my car is my summer daily driver, i want to keep seating for 3 people, or you know.. a place to put my school bag

and since i'm an engineering student, i designed it too hold from towards force from a body restraining harness, and the downwards force of a possible roll over

so, the big green bar would be 2'' cromoly tubing, flush to the roof, and flaten at one end to bolt to the seat belt pivot, and maybe with a camera mount at the other end, directly in the middle of the car
this bar would be powder coated to hold against the rubbing of the harness, since the harness would be strapped directly to it

the small green bars would be 1/2'' solid aluminum (or steel, in worst case)
the red parts are adjustable threaded bits
the forward facing bars would be bolted to the rear 'front seat mounting points'
and the rear facing bars would be bolted to the rear 'seatbelts mounting points'
all those small bars would be connected to the big bars by helm joints

the height of the harness mounting bar, would make it so that the angle of the harness would be 15deg (FIA approved)

tell me what you guys think

[fastbmw7]

It won't work very effectively as a roll over bar. The top of the bar is not braced. (Even roll bars have vertical braces that support the bar at the top and run rearward (and down).
Relying on the seatbelt mounting bolt holes to provide roof support in a roll over would be unwise. Look at roll cages and you will notice that the mounting "pads" for the base of all tubes is a rather large plate placed thusly to distribute the load as much as possible. Your small supports anchored at the seat mounts don't quite cut it either.

[hozer]

How about adding a horizontal bar spanning the width between your roll bar vertical uprights? You could then attach the shoulder belts to the crossbar and dramatically shorten their length which is better, (meaning less stretch).

That's what I'm doing lol!

[frankiman]

well its not supposed to be a full on roll bar, since i would have to say goodbye to the rear seats to make one,

but this is just a compromise, while im making a harness bar, why not try to make it as a type of roll bar too

and 4 1/2'' aluminum bars placed in a triangular way, can support up too 1200lbs easly
its just there to help the roof its self

and as you can see from this pic, ive already had a roll over with my previous GTR and the roof didn't collapse much

[DarkCaporaL]

While on the subject of harness bars again, I was wondering what difference does it make if you have racing seats?

As in with the seat bucket, the harness goes through the top *holes* in the seat, and then get attached to wherever they are, and thus creates that support point like a harness bar does it not?

Like this:


I'm just wondering what added benefit the harness bar would add? Maybe because it's more rigid than the seat?

[hozer]

While on the subject of harness bars again, I was wondering what difference does it make if you have racing seats?

As in with the seat bucket, the harness goes through the top *holes* in the seat, and then get attached to wherever they are, and thus creates that support point like a harness bar does it not?

Like this:


I'm just wondering what added benefit the harness bar would add? Maybe because it's more rigid than the seat?

The problem with just using the seats like that is the structural composure of the seat (foam and plastic) is not something I wanna gamble paralysis on... This being said, I do think that in a minor collision (5km or a "typical fender bender") that the seats would serve well as a pivot point.
Simillar to the roll cage, I believe that a harness bar is simply risk managment. Am I gonna need it? Who know, but the couple hundred bucks it cost to do it all right could save me being confined to a wheel chair

[m_melen]

i think somebody needs more practice with photoshop lol. looks cool though

[frankiman]

hey!
took me 3 minutes with paint shop pro
i'm not baller enough for photoshop

[Velders]

Time to bust out solidworks and draw it up, and run it through cosmos.

[frankiman]

alright, gimme a day or two, my solid works is on the fritz, maybe ill have to use catia

[Velders]

Haha i was just kidding, but if your bored why not. My solidworks only works on my computer that is crap so its pretty useless to me.

[DJ]

any updates on the fitement of the s13 bar?...

[hozer]

No from anything I've heard, think Im gonna have to get one fabbed