bpu699

Just finished roughing in my roll bar. With the fixed back seat in, my head is about a foot ahead of the roll bar. The bar itself is in line with the a-pillar or a couple inches behind.

All the info I can find on the Internet says my head needs to be 6 inches or less from the bar... I can mount it that way, but then the rollbar is ahead of the a-pillar...

How is your mounted???

Further forward is great for possible roll overs, but bad for street use. If its mounted a foot back, your head will get hit in a rollover...

So, which is correct?

To me it looks like all the Porsche rollbars are behind the a-pillar... Some, like th Patrick motorsports, looks way back...

rlm328

My roll bar is aligned to the A pillar (windshield) and B pillar (back of the door).

bpu699

Meant to say b pillar, not a pillar. Looked at dozens of rollbars in 911s and all of them seem to have the roll bar behind the b pillar...

But if I do that, and install my cobra Suzuka seat upright, my head is a foot away. Fully reclined, it's 6 inches away, but the front of the seat rides pretty high...

Is that normal?

NYoutftr

Here is a picture of my Dassport
996 C2

bpu699

Thanks for the picture...

When I have my stock seats, it looks just like yours... so how far is your helmeted head from the top of the rollbar? less than 6 inches?

With the fixed back seats, they don't recline. So, mounted flat, the back of the seat is 1 foot from the roll bar. Reclined, the back is 6 inches, but then the front of the seat rides pretty high...

Is that how folks mount it?

linzman

Ah, the trusted Internet. I have never heard this before, where exactly did the info come from?

Dave 86 930 Fl

Right now, about 34 miles.

bpu699

Is that wrong? If I google helmet to roll bar distance several sites pop up recommending 6 inches. Including a book on making or installing roll bars...

Personally, don't really like that idea much. But with the seat upright, and my helmet on and a foot away... I can see how in a rollover my head would get hit...

How far is your head from the roll bar?

Bo

jj1

A well built cage is typically built considering the drivers seating position. If you buy a bolt in, the bar is where it is. In general, a roll bar/ cage makes a car less safe on the street. On track, you use a helmet, HANS and fixed back seat with your bar or cage. So hitting it isn't much concern. If it is you pad those areas of concern.

fatbillybob

Any bar that is 1 ft from your head you can hit with your head due to body deformation, belt stretch, etc. So it is better to put the bar closer to the head and pad it. General rule of thumb is to pad any bar within 6" of the helmet. I go a foot. The halo bars are the issue where there is easy contact. So have them close and padded SFI 45.1 padding. My full containment seat head wing and the padding from the halo bar are flush with each other. The hope is the car crushes and decelerates you and throws off energy while the cage does not deform. The front of the halo is easy if you place the bar forward of the OEM sheetmetal halo. There is a 2" over your helmet rule of thumb for the height of the rollover hoop. That is difficult to achieve at times. Most coupes slope the further back you go so if you place the hoop rearward for 1ft clearance you lack the proper height of the hoop. So the hoop will be near your head so just pad it and go for the height clearance you need. so extra mitigation is found in the 7th point harness which is basically a 6pt harness with the old 5pt substrap making 7 points. Your basic schroth harness cam already can do this just buy an extra strap for the 7th point.
6pts give you better frontal crash pelvis control that's why they made them. But the old 5pt gives you better rollover control. Going 7pts gives you the best of both words and no downside except cost and more tings to buckle. The seat controls what you can hit. So make it a good one...a full containment one.

NYoutftr

[QUOTE=bpu699;13511232]Thanks for the picture...

When I have my stock seats, it looks just like yours... so how far is your helmeted head from the top of the rollbar? less than 6 inches?

About 7"-8"

No idea what kind of Bar/ cage you are installing, I am guessing that it is a weld together unit.

bpu699

[QUOTE=NYoutftr;13516026]Its an autopower roll bar that I am modifying, and partially welding in (hate how the feet mount)...

bpu699

Thanks for you ongoing input, I have learned a lot from your posts on here and fchat...

Roll bar going in, have schroth 5 point belts, and will pad the bar... Just trying to learn as much as I can...

Still trying to get comfortable with the idea of attaching a bar to the back of the seat, as a back brace...

rlm328

The back brace is not normally attached to the seat but is a plate that the seat back is supported by. The brace is attached to the roll cage. Once the brace goes in your seat sliders will lose a lot of there functionality.

Aspen Autosports

We were just talking about this in another thread. https://rennlist.com/forums/racing-a...this-safe.html