This is why....

Marty Howard · **Posted:** Tue Oct 27, 2009 2:00 pm

How you install the rollbar is just as if not more important that the rollbar itself.

Bolting it to the plain sheet metal of the floor pan just doesn't work.

Dustin Fredrickson · **Posted:** Tue Oct 27, 2009 2:31 pm

Was there a story along with these pics? Looks fatal, at least assuming harnesses were used with those race seats.

Steven Carter · **Posted:** Tue Oct 27, 2009 2:34 pm

more pics with usual cheeky commentary....

http://jalopnik.com/5390934/mustang-cov ... -tire-wall

Glad no one was hurt.

edit: I'm no racetrack manager/designer, but I thought tire walls were supposed to stop cars, not compress into ramps, thus enabling cars to go airborne.

Marty Howard · **Posted:** Tue Oct 27, 2009 2:48 pm

Kevin Harvey · **Posted:** Wed Oct 28, 2009 8:40 am

You know, I have seen everyone and their brother on the internet poke fun at this incident as well as the mounting points on the rollbar.

Guess what? It looks to me like it was mounted per the Autopower installation directions. The same installation that we pass as safe for our own track events.

The Autopower rollbars in both my Mustang Cobras were mounted in this same exact floor pan configuration. Was it the safest possible mounting? No, and that is obvious by the pics. But it is per the manufacturers installation instructions as well as SCCA/THSCC guidelines.

Just something to think about.... I will say that if we start requiring rollbar installations to have a tie-in to the frame, we will severely decrease our participation rates. To include a lot of our own members.

Sorry to rant...

Marty Howard · **Posted:** Wed Oct 28, 2009 8:50 am

The rollbar was a street bar with no diaganol support. There is a lot of initial speculation that the lower bars spread starting a tear in the sheet metal. This lead to the overall failure.

So most likely it was a combination of issues.

Jason Mauldin · **Posted:** Wed Oct 28, 2009 9:09 am

I tend to agree with Kevin.

These bars aren't designed to support a car being dropped on it's roof. I think we've seen proof of similar bars working well in a rollover situation, so I would think that they do provide additional benefit to the OEM structure, they just don't help much in a situation where the car falls flat on the roof like that.

Jason Mauldin · **Posted:** Wed Oct 28, 2009 9:12 am

There is also an alternative bar for the Mustang that looks like it would provide more protection than this bar.

Two different bolt-in roll bars for the S197.

Maximum Motorsports (left) - Autopower (right)

Also keep in mind that they came out of that car relatively unharmed. I think something slowed down that smash enough to provide some kind of protection.

Kevin Harvey · **Posted:** Wed Oct 28, 2009 9:15 am

I hear you Marty. I jumped in on this because I have seen way too many threads on the internet over the past couple of days criticize the rollbar, the mounting point, that particular shop (I do not know them and have no affiliation), etc..

I am not a mechanical engineer, but I would think that whether or not the bar had a diagonal would not have mattered in that specific wreck. The way it flipped over, it put a massive amount of force directly onto the hoop and into the floorpan.

On the flip side, I have seen rollover wrecks in cars (Mustangs specifically) where a street bar did a great job of protecting the occupants. In those instances, the bar never received a direct hit and was never forced through the floorpan.

From owning two Cobras, I can personally tell you that the floorpan is very thin and it takes very little force to make them flex. I am willing to bet the vast majority of cars out on the road are just as thin.

Kevin Butler · **Posted:** Tue Nov 03, 2009 11:05 pm

This kind of event should also make one think twice about the safety precautions they provide for themselves and the speeds they are driving.

The 350Z that endo'd across China Beach at Mid Ohio last year started me thinking that replacing the roll bar in the SC'd Miata with a welded in cage would be a good idea.

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

I must take exception with the blanket statement about bolted in roll over structures. Bars and cages with correct mounting and bar member designs are quite safe.

Having designed, built and tested several, plus examining numerous instances of their performance in rollover situations I think I can speak with some credibility re this subject. But don't take my word for it, talk with Tom at Hard Dog. Y'll are familiar with Tom and his reputation, right? ;')

Note that this post is specifically referring to base mounting to the frame, and if done correctly, to the floor pan. While bar member connections are more problematic they can also be done in a safe manner. I also have experience with these, and would put the type of connections I used up against most other methods in any situation. Which FWIW are different than those normally seen in most commercial designs where expedience and cost are paramount.

While I can't see as much as I'd like in this instance, I'd bet that the cage, it's members and their connections are the greater contributor to this failure, notwithstanding the above photos.

I would also like to point out that welded in installations have been known to fail due to inadequate design and installation.

OCTJMO, ICBW,

Steve 'donning 'is triple layer Nomex anticipating the inevitable flames' Coleman

RobLupella · **Posted:** Thu Nov 19, 2009 2:09 pm

Hmmmm I see the beginnings of another 9 page rollbars are worthless, rollbars are God's gift to safety thread starting :twisted:

Steve Coleman · **Joined:** Sun Nov 13, 2005 9:50 pm **Posts:** 188

RobLupella wrote:

Hmmmm I see the beginnings of another 9 page rollbars are worthless, rollbars are God's gift to safety thread starting :twisted:

Inconvenient perhaps... but worthless ? when you need it ?

Ridiculous !

Sheesshhh...

Steve 'who's been sans bar, but not cause it's worthless' Coleman

Chris Brown · **Posted:** Thu Nov 19, 2009 3:01 pm

Steve Coleman wrote:

I must take exception with the blanket statement about bolted in roll over structures.

i think you are taking exception to a non-existent statement steve.

the statement i think you are referring to is

Quote:

Bolting it to the plain sheet metal of the floor pan just doesn't work.

which is talking more to installation than style.

Marty Howard · **Posted:** Thu Nov 19, 2009 3:14 pm

agreed.

The discusion was about the installation methods, not about the bolt in bars themselves. Some of the bolt in units are VERY well made, like the Hard dog ones.

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