Sun Ra

mike,

thanks but in my case i'm slow! but getting faster!

pig4bill

There's one statement from that article I'd really like to see some tech on:

A lot of racers use no padding at all on their rollbars. My understanding is that a helmet does not need rollbar padding to function properly. I've always been told from way back when that rollbar padding was supposed to prevent your arms and legs from being broken when they flail about in a crash. If that's the case then the padding should protect your skull as well.

At the very worst, danger to your head from a rollbar in a street crash is not from the belts or harness you use, it's from the seat. If the seatback collapses or flexes enough, you're in trouble. That's why most race sanctioning bodies require a brace for the seatback or an FIA (i.e. shell) approved seat. If the dimensions of the seat are such that it wouldn't let your head hit the rollbar in a full recline, I'd say you're okay. Porsche seats have integral headrests so it's likely this is the case.

Boqueron, as to your original question, don't dismiss too lightly the statement that race harnesses may not be DOT approved. If you had an accident, your insurance may not pay your hospital bills. They might claim it was your fault since you were using non-DOT belts. You might want to check with them.

boqueron

A very interesting point ! I will check the legal situation in Spain. Also, when you are talking about the Porsche seats, are you refering to the regular seats or the GT3's ?

pig4bill

Obviously Euro GT3 seats, or any other shell-type seat, are not going to let your head hit the rollbar in a crash. Where you would need to check, is the traditional seat that reclines. The danger is that in a severe crash, the seatback would collapse, and possibly allow your head to hit the rollbar. Since Porsche seats generally have the headrest built-in, and many rollbars have some sort of harness or camera-mount structure directly behind the seat, that may not be a danger. You would have to check on a case-by-case basis to see if a fully reclined seat would put your head in danger.

Worst case, you may have to install a seatback brace, similar to one required by most U.S. race sanctioning bodies.

boqueron

Thanks pig4bill

SundayDriver

I'll start with a disclaimer - I am not a safety engineer. I am a mechanical engineer and worked for quite a while in the auto industry, but never in crash testing or safety. So take this for what it is worth...

I'm afraid there is no really good answer for you, Watt. There is lots of data on stock configurations. There is good info on race setups with full cages, helmets, etc. Unfortunately there is very little on solutions in between.

Yes, they are saying that a rollbar is dangerous to have on the street. You will have to decide what to do, but here are some of my thoughts. Clearly, a full cage with bars sitting next to your head is very dangerous on the street. A minor side impact could drive your head into that bar, which is a bad shape, and you could get killed in a 10 mph side crash. Padding isn't going to help. For a rollbar only, it is not quite as obvious. The bar sits above your head and behind the seat. It would appear that you would not hit it, but I am not so sure. Having seen lots of crash videos, I am constantly amazed at the amount of deflection in all parts and the stretch in the belts. I can envision where a rear impact could deflect the seat to the rear. With belt slip/strecth, it seems quite possible that you could hit the roll bar.

You could brace the seat, but you really don't know what that would do in other situations. Some race seats are meant to not be braced so they car deform to their design and control g forces. That is typical of the problem - you can't really know what danger you might be introducing.

My opinion - if it were my car for track use, I would add a rollbar and keep it in on the street. I think the benefit of the bar is greater than the risk. But I am also one of the guys who thinks it is safer to run 5/6 points without a bar than to stick with 3 points. Those are all choices with downsides.

You pays your money and takes your chances. It is dangerous on the track (and street). Good luck

Sun Ra

thanks mark.

how do you run 6 points in a 911 with out a bar or harness bar?

SundayDriver

Watt,

You need either a rollbar or harness bar that will route and support the shoulder belts. I am not sure if any seats are suitable for supporting the harness (without a bar), but I would doubt that.

Chris Y.

What do you guys think about this harness bar???

http://www.bkauto.com/porsche/r1035.php

Quote from www.bkauto.com website: "The R-1035 been tested and certified by an independent lab to handle the types of forces required by the National Highway Traffic Safety Admin. DOT and SAE J385 Rev.MAR 95, Motor Vehicle Seat Belt Anchorages-Performance Requirements."

It's even DOT approved...the question now, is any harness DOT approved???

-Chris

pig4bill

Are you talking about the belt angle or the danger of the shoulder belts slipping off your shoulders? There are many seats with the harness holes that should keep them on your shoulders. As far as the angle, 911's are probably better suited than most cars. Like a BMW sedan would have no good place to mount the shoulder harness at a safe angle. 911's have the bulkhead, and I thought I remembered years ago somebody selling shoulder belts that mounted to the rear seat hardware. Some people might not like the long run of webbing, but there used to be a school of thought that a little stretch in the belts was good because it cushioned the shock. Like for climbing rope, the stuff that doesn't stretch is considered crappy.

HarryD

My Stroth Rallye 4's are DOT Approved.

SundayDriver

I was only thinking about belt angle and how much force would be placed (downwards) on the seat. I have no idea if seats are designed to take those forces or if the belt entry to the slots needs to be close to horizontal.

SundayDriver

BK makes good stuff so I imagine that is a good harness truss. However, I don't think it is DOT approved. What they are saying is that it is tested to similar forces. As HarryD said, there is a DOT approved 4 point system. I have always been concerned about that system though, as I don't understand how the lap belts are held in the proper position with upwards forces from shoulder belts. (I am not saying they don't work, only that I don't understand how they work.)

Dirt Track Racer

You couldn't pay me enough to use 4 point belts on the street or the track.

DTR

pig4bill

The ideal angle between seatback and shoulder belt anchor is supposed to be 90 degrees. If it's much more severe than that there's a danger of your spine being crushed if the shoulder harness slots are too low or the seatback being levered off if the slots are too high.

DTR, are you able to share more details about the crashed M3 discussed earlier in the thread?