Z-man

What are your thoughts on bolt in roll bars for DE events? Specifically, ones that bolt into the rear seat belt anchor points.
Do they provide sufficient roll-over protection?
Are they only marginally better than no roll-bar?
I would prefer to have such a roll bar for ease of installation & the fact that I won't have to rip apart my interior, but if they are worthless, then I'm better off not bothering.

BTW: My car's a 944S2: ya know, the Porsche with the engine in the wrong spot! <img border="0" title="" alt="[Eek!]" src="eek.gif" />

I know of a company: redline rennsport that makes custom bolt-in roll bars for the 944. Anyone familiar with other such companies?

Thanks,
-Z-man.

M758

PCA club racing just annouced that roll bars anchoring to the seat belt mounts would not be legal since they load the bolts imporperly.

Of course this is not DE, but
I would guess that the a seat-belt bolt in is better than no bar, but I would rather just install a proper bolt in bar. If done carefully you can still keep the interior nice. A friend installed an Autopower unit in his S2 Cab. He still concours the car with good results.

Carrera51

That's interesting because Performance Products is selling the DAS rollbars and they advertise them as PCA club race legal.

M758

Check this months Club Racing News. It is avalible on the PCA national website.

Dan Gallagher

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Z-man:
<strong>What are your thoughts on bolt in roll bars for DE events? Specifically, ones that bolt into the rear seat belt anchor points.
Do they provide sufficient roll-over protection?
Are they only marginally better than no roll-bar?
I would prefer to have such a roll bar for ease of installation & the fact that I won't have to rip apart my interior, but if they are worthless, then I'm better off not bothering.

BTW: My car's a 944S2: ya know, the Porsche with the engine in the wrong spot! <img border="0" title="" alt="[Eek!]" src="eek.gif" />

I know of a company: redline rennsport that makes custom bolt-in roll bars for the 944. Anyone familiar with other such companies?

Thanks,
-Z-man.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">redline is making a batch of bars right now (mine is one of them) if you want one i would hurry up and order it or you will be waiting for a very long time (i paid in november or december).

smokey

I have the redline roll bar for DE, and I believe it's better than nothing but not as good as a cage or weld-in bar. The two grade 8 mounting bolts in shear which attach it to the seat belt inserts have a combined yield strength of about 26,000 lbs by my calculation, so with the strength of the roof added, the bar should be able to withstand an impact of 10 g's. This should cope with most roll-overs, but not a high speed endo with the car landing on its roof. A welded-in cage is the only thing that could possibly deal with that. I'm not sure anything welded or bolted to the floor would do better than 10 g's, but I haven't done the calculations. The limiting factor on anything attached to the boxed side rails is probably the buckling of the tubes. In any tubes that extend to the extremities of the car, you have to consider the reduction in crush space that results, and also figure out where the tubes will end up relative to the driver in a front or rear collision. S0---- there is on easy answer. You can actually make the cage so strong that it increases the forces acting on the driver in a collision.

PeanutinCA

OK, so the cage mountde to the seat belt mounting points with two small bolts. Your car rolls and the bolts at the rear mount (for example break), where is the cage going? Mine is still mounted to the cross bar, another two points. So if all those break, at this stage the roof is somewhat crushed around the bar, where is it going? I could be wrong but, as soon as the bolts sheer off, would the bar end start pushing through the sheet metal? I can't see the bar going anywhere? Unless it's completely different in a 944 to a 993? Just some thoughts.

Dylan.

Adam Richman

First, I am not a structural engineer nor a fabricator nor did I sleep in a Holiday Inn Express last night but the only way I'd comment is that as an instructor, I'd ask for another student. I hope that doesn't sound mean and I am probably in the minority of instructors on this. Be that as it may, I'll instruct any student in any hardtop car with stock seats and OE belts but if there is something behind me that prevents my seat from collapsing rearward (incl. running race seats and no rollover protection) and something I'm uncertain would keep the top from collapsing, I won't get into the car (and this, after seeing some cage deflections at a recent school goes for some bolt-ins as well).

I can tell you from personal experience that you can remove everything necessary to weld in a roll bar to the rockers and still be able (via cutting the bars out at a later date) to return the vehicle to its original state (minus the welds in the wheel well which undercoat could fix in 5 to 10 minutes).

JMO and be safe.

Z-man

Thanks all for the feedback.
Of course, now I'm no closer to any final solution!

PeanutinCA: you make a good point of the bolt-in bar having nowhere to go, and still providing some roll over protection.

But per Adam Richman's comments, a detached bar may get in the way of the seats, and the wrong type of setup can exaggerate the effects of a rollover. Adam: I'm running in White run group (intermediate) and feel that some roll over protection would at least give me peace of mind: I am going a little faster than when I started this craziness!

Still dazed and confused,
-Zoltan

Adam Richman

Z-man, just to clarify the "getting in the way of the seats" comment. I am not sure if you recall but there were two cars _flattened_ about two years ago at Summit Point (E36 BMW) and Buttonwillow ? (Mustang) and fortunately in both cases, driver and passenger survived (and these were HPDE students in both cases IIRC). There was no rollover protection in the cars and the stock seats + OE 3-pt. belts allowed the occupants to slouch a be "mushed" by the car - if they had been locked upright by a harness or race seat ... might very well have ended up much less fortunate. I don't like the idea of a roll bar secured by 2 bolts, after seeing floor pans replaced on a race car, I do not feel a bolt-in that attaches to the floor pan to be remotely safe either (punching through). These are my concerns and put them together, I'm comfortable in a 3pt w/ no rollover protection OR 5/6 pts, race seat and appropriate rollover protection. This - of-course - is only my stance and doesn't reflect all instructors/drivers. I, as I have with my friends, would vigorously try to convince you that you should seek out a reputable cage builder and have him "weld" you a 4 pt. roll bar to the rockers and rear wheel wells AND use FIA approved seats IF you want to use harnesses because your current speeds dictate some change for your peace of mind.

Now, after a 10 hour round trip to pick up my freshly painted race car, I'm going back to work

Peace!

ninefiveone

Lets clear some things up. The redline bar is attached via four grade 8 bolts. Two to the rear outboard lap belt mounting points and two to the rear shoulder belt mounting points.

I wouldn't claim that this is the ultimate in roll over protection but if you do the math and the geometry, it's a sound concept. Particularly for a DE car. Since no one has rolled over in a car so equipped, there's no hard proof. Of course, I hope that proof will never materialize.

Anir

Interesting thread.

I'm in my 3rd year of DE's and just installed two Recaro-built GT3 seats, a DAS bolt-in bar, and 6-pt Teamtech harnesses (mounted to the car for the lap and shoulder belts, but the front of the seat rails for the anti-sub belts).

My goal was to stop sliding around in my stock sports seats, because this resulted in a sore left leg after each event (from bracing against the dead pedal) and forced me to use the steering wheel as a brace as well.

I decided that the DAS bar was a better alternative to a BK harness bar or truss. I fully realize that a fully-welded cage would be superior, but the 993 is my daily driver and I felt that compromises are necessary.

I do look forward to getting a dedicated track car at some point so I can do this properly, with respect to safety and dedicated track suspension, tires, etc.

<img src="http://boards.rennlist.com/upload/GT3interiora.jpg" alt=" - " />

** Please note that the pic was taken before I started drilling to put in the Teamtech harnesses.

Peter Kelly

A couple of years a go there was a photo on the DAS site of a 911 that rolled at Lime Rock with their rollbar in it. It (the 911) came through pretty well.

Ed Newman

I think simply put, a roll bar, even if it is bolted to the seat belt positions, is better than nothing. In one particular incident I saw on the track, a bolt in roll bar did appear to improve the structure of the car during a severe side impact. The car hit a grouping of trees sideways on the passenger side. Thankfully, no one was in the passenger seat as it door, roof and floor completely collapsed into the passenger seat. The roll bar was bent but appeared to have minimized the impact to the rear section of the car. A full cage would definitely have helped the situation adn would have made a huge difference if a passenger had been in the car.

Dave in Chicago

Good thread. I use the RedLine bar for my daily driver (snows just off yesterday) / track car. Usual disclaimer: no commercial interest, just a satisfied customer. My view was that it was a step up from "harness bar" install with only moderately more cost. For me, it was a solution to a very specific problem, i.e. using the car for work, kids, camping, etc. and being able to convert it to DE duty quickly and easily. To that end, it is great. I can install the bar, my 6-point Schroth's (BK clip-in mounts, stock seats), extinguisher, yank the mats, empty the glovebox, etc. in about 30 minutes. De-equiping the car takes even less time.

If your needs are similar, it's a good rung in the ladder of increased safety. Would a welded-in bar be even safer? Sure, I believe so. Would a full cage be the best? Yup, seems no doubt. One just has to pick their spot in the safety ladder.

Now, if I can only convince the wife that she can climb into a car with a full cage while wearing a dress... You see where this is going.