Originally Posted by
denkimi
Yes it is. It functions as a crumble zone for the body. It slowly absorbs the energy that of the occupants body that would otherwise get abruptly absorbed by solid things like the steering wheel.
In fact, being constrained by a bucket seat and a 5 point harness is worse than being constrained by airbags. If the car comes to a solid stop, bucket seat make your body also come to a solid stop, creating enormous amounts of G's. If you are constrained by an airbag, the impact is spread out over a longer time, drastically reducing G forces.
But the issue with airbags is that they only work in one direction, while a crash can come from anywhere. Plus, rally cars are filled with big metal tubes and little space to actually move, making seat and harnesses a more reliable solution.