Door Opening "X" Bars as Side Protection

[splats]

As an EX-circle tracker, I've had my share of T-bones & got hurt several times. And those were less than 60mph. Turn 1 at Sebring is a blind, 100mph turn. We built as strong door bars as we could. You can't see from the pics, but there are as many triangles in the bars as could get. All three horizonals are bent different. And the center bar will HOPEFULLY deflect front bumpers down. As with any cage, you can find a weak point with mine. If you see something that we overlooked, please let me know. When people talk about the cage adding weight, consider this..... my car is just 50lbs over the minimuim WITH 3/4 tank of gas (stock) & the spare tire still in the trunk. I'm glad that Richie is OK. But I'm supprised that no-one has gotten hurt because of building to the rules. If you can just open your door & STEP into your seat, IMO you don't have enough protection. I'm more worried about WALKING away from a crash than walking away with a placque. Sorry about the soapbox, but we just had this talk at our district meeting recently.

[zchris]

Well I am glad Richie is OK. I am the one who built the cage in Richies car. I wish Rich had let poeple photo the damage as that is the only way we all learn. I think the Taco shell idea would solve that failure mechanism. I also think that foam filling the door would be the lightest and safest fix. The foam would absorb the energy and distribute the load over a larger area. I think this is common in Rally cars in Europe. All my Rally car customers have the Taco shell setup as they are required to have an X brace on both sides. Ultimately, Nascar bars on both sides would be best. Most of you guys just do not want the extra weight and cost. The other thing to remember is that you want the car to absorb energy in the impact, not you. Nascar got to the point that the cars were built so well that the car survived most any crash. Unfortunately the drivers were not. Its a balancing act between rigidity and crash worthyness. In one of Dick Shines early cages I built, the driver hit the wall in the oval at NHIS and rolled down into oncoming traffic. He was rearended so hard the drivers floor tore under the seat. We had built the rear to be so rigid it transfered to much energy into the drivers area. From the rear shock towers to the back of the main hoop was fine. Not a great design in that application. As always I am happy to build what the customer wants. Unless its a real disaster. Lets all try and learn from this. I wish crash testing was not so expensive.
Chris Howard
HowardMotorsports

[raffaelli]

Chris, glad you posted here. I am pleased to hear that you built Rich's cage. You built my cage and I am very confident in it. The design, from what I saw, in Rich's car is the same as mine. I now see that your work will allow a driver to walk away under such severe conditions. Kudos. I'll be ringing you this winter for some 'extra' bars.

[RSTPerformance]

Chris built our cages in the Audi's as well.... Very well built IMO.

We have the standard "X" bars like sandro does in both drivers side and passenger side. Many other people I know have the same thing... I think that it is obvious we need to make an upgrade or two. One thing we have wanted to do forever as put in a petty bar. Now I am also thinking that we should weld in a few "Taco's" (is that the real name for the sheet of metal reinforcing the area where the X is formed?). Do you think this would do the trick, or do people really think that it is necessary to take out what is already in the cars and put in NASCAR bars?

Raymond

[Sandro]

[quote=RSTPerformance;274129is that the real name for the sheet of metal reinforcing the area where the X is formed?
Raymond[/quote]


thats just what I call them because when done like the picture below they look like a taco

[rsportvolvo]

I think something here is being overlooked. We are looking at the car's damage and thinking it's bad to see a car THAT damaged, even though the driver escaped without injury. We should be looking at the car as a sacrificial anode in that the structure successfully absorbed the force of impact which allowed the driver to survive.

The X-brace and stock sheet metal deformed (I don't like using failed here as it really did it's job) during the impact. During impact the structural pieces deformation absorbed a significant amount of energy. That energy absorbed was not transferred to the driver.

Now if said driver had NASCAR bars on the passenger side the structure, in theory, would have deformed much less (that is the arguement here, right?). That means the load would be transferred elsewhere and ultimately to the driver. Not a good scenario either.

I want a structure that protects me from intrusion, but not at the expense of my bodies G-loading. The FIA has performed a lot of impact studies and requires impact test on as raced monocoques and shells as part of vehicle homologation. I should look into getting more information on this.

I'm actually a fan of impact absorbing structures and foam as used on FIA cars, Rolex Daytona Prototypes, and NASCAR COT. It is unfortunate that this safety technology has not trickled down to the club level yet, at least not here in the USA.

Unfortunately I don't know anyone besides Crawford Composites or DOW making such structures and foam, respectively.

Also, I spoke with the RaceTech folks last year at the PRI show about their seats with the integrated seat back bracing mounts (I think this is the Viper seat). They tested the seat to @ 45 G load where the FIA only requires something in the 20 G range. Customers have sustained upwards of 85 G impacts without significant driver injury. Something to think about.

[rsportvolvo]

thats just what I call them because when done like the picture below they look like a taco

Gusset is the correct term.

They should match better too, e.g. make a rectangle or square.

[Speed Raycer]

Yes, gusset is the correct term, but there are a WIDE variety of gussets out there. That style is commonly referred to as a Taco Gusset because of the shape/form.

Kudos to Chris for building a great cage that kept the driver safe. The chassis' are expendable. Glad the driver came through it OK

I'll reiterate (sp?) what Chris said... it is sometimes close to pulling teeth to get guys to upgrade from the minimum. PLEASE stop trying to save money on the cage end. I've had guys request that I NOT put any gussets in because they didn't want to spend the money. How about using those HoHo's for 2 weekends instead of new shoes every race

It's a shame there aren't any pics as they would have taught us something.