Larry Herman

John, I see what you are saying. In the first pic I see that there is a lower bar at the sill level. It looks better than the "floating in air" style.



Here you can see a complete Nascar cage, and it looks like the verticals are tied to the sill frame and the side hoops.

RedlineMan

Indeed, Larry;

Here's a good example.



Far beyond the simple mass of tubing that the door bar itself consists of (which is fairly strong in and of itself), there are multiple layers of material and structural redunancy built in behind it. The black arrows point to the direct support for the door bars; the side and rear hoops, and the large rectangular section frame tube at the bottom. The blue arrows point to secondary support tubes; the belt bar, a crush bar below it, the dash bar, the angled bar at the window opening, and even the front seat frame bar on the floor. The yellow arrows point to supporting members even further down the list that are sending forces off in many different direction and to different parts of the chassis. I'm sure there are corresponding members at the rear that we cannot see in this photo.

All this by way of saying that the NASCAR bar does not work structurally without its foundation. No uni-body-based sports car has this. Ironically, the passenger side of that Bimmer you pictured might have better intrusion protection than ther driver's side!!

DanR

^ it is interesting though, as there were a few post early in the thread about the center roof bar being unneccessary, however that is the same as the NASCAR (as opposed to the usual x design

RedlineMan

Correction;

The real exception is that it might be less than optimally placed, not that it served no purpose. If you end up laying on your side with your roof facing oncoming traffic, well placed bars of this type take on new gravity!