I'm not sure if this link will work properly, but if it does, it leads to a very telling photo.
If this is the pilot's posture during a race, it would not be very good for high G loading. He appears to be using a typical airline/corporate shoulder harness that joins in a V and then connects to a inertia reel. (You have to download the image and zoom in to see this. A little tweaking on the contrast and mid tones helps as well).
I realize he probably has to sit like this to see the pylons and other aircraft, but with his head not against any support and turned to the left and down, even if the g loading was only 4 or 5 (not 20 as the media is claiming) he is in a very poor posture to deal with it.