mousecatcher

For a C6 Z06 application, I'm wondering if a 4 point rollbar installation negatively affects or is negatively affected by any rear crumple zone? For a car with back seats, ISTM a roll bar is almost a no-brainer. But for a 2 seater, would the rear part of the roll bar prevent the crumple zone from working as intended? I'm assuming the entire rear of the car behind the seats is a crumple zone. Maybe that's not true.

hmm, I take it back. Surely the fuel tank isn't inside the crumple zone?

Along those lines, and again c6z06-specific, doesn't the fact that the roof is integral to the frame suggest that the car already has at least some rollover protection?

fatbillybob

I don't know the answer to your question but have often thoguht of these issues as well when designing the rollcage for my racecar. My thinking is anything fore or aft of the shocktowers is crumple zone. It seems that racecars run tube to the suspension towers all the time so I guess it is o.k.. I would guess in a C5/6 that the rear cage feet stop at a line along the shocktower and bolt/weld into the frame rails. But if you want real rollover protection you really have no other options

RacePro Engineering

MouseCatcher,

I am unclear as to your questions, but obviously you are wondering about safety in a crash or rollover.

While any hard top street car offers SOME rollover protection for driver and occupants, the question is, "Is that enough?" Perhaps for most street driving, it is. Certainly, for road racing, it is not. In this case it depends upon your useage.

The other part of your question, having to do with "deformable structures", is an area where we have some knowledge. For racing cars, current best practices dictate that, in an impact, there should be progressive collapse and break-away of structures. As the pieces around the perimeter of the car "Crumple", the energy of the impact is disipated GRADUALLY, AND as the intrusion attempts to come further "into" the car, it is met with ever-increasing resistance. However, when we are speaking about a roll bar or cage, that structure is the point at which the intrusion MUST STOP!

From a racing point of view, the entire car outside of the cage is a "crumple zone" - and so it should be!

Ed LoPresti

mousecatcher

Let me clarify a little.

I'm talking about a dual-use (street/track) application, and I'm only talking about a roll bar, not a full cage. I'm concerned about the safety of a roll bar *on the street*, not when on the track. I'm confident that on the track, with harness, helmet, etc, the roll bar is no-question better.

But on the street, I'm worried that the 2 rear extensions of the roll bar stiffen that part of the passenger compartment behind the seats beyond the manufacturer's design, so much so that too much force is transmitted to the driver/passenger and not absorbed by the car.

Now in comparison to a "race car" or even some generic street car, ie steel frames, perhaps that area is not part of the crumple zone. But with the aluminum frame of the c6z06, maybe the crumple zone is larger and a roll bar stiffens that part of the chassis too much?

For example, the wikipedia entry for "crumple zone" says "The 2004 Pininfarina Nido Experimental Safety Vehicle locates crumple zones inside the Survival Cell."

mousecatcher

here's an interesting article: http://www.356registry.org/Tech/roll...reet-cars.html