Quote Originally Posted by Mirek View Post
The issue is that penetration of a rally/race car by an object with small cross section is virtually impossible to prevent because the kinetic energy of the car is way too much for creating any sort of working protection. Moreover in most cases the objects penetrates the cockpit through the windshield or side windows. Even if you put a bullet proof glass (which is super heavy) it will not be enough to prevent penetration by something like a steel pipe at higher speeds. It's not an issue of a tube frame.

Just to illustrate what I am talking about. The WRC car with the crew weights around 1400 kg. If it is going 100 km/h it has a kinetic energy equivalent to a shot from this.

If you have an object with a small cross-section it will penetrate whatever you can build into a car. I remember I saw a railguard penetrating an engine block of a BMW X5 in a Kubica-style accident.
i will use fourmaux again as an example:



there is just nothing to stop objects coming in from the side. even things that would create just a big dent in a normal metal door could become lethal in these plastic cars.
They added a second hoop, but they should have also added a 1 or 2mm thick metal plate between the hoops and between the X in the doors instead of just foam.
it would add just a few kg's at max, but that would be the same for all so it doesn't matter.