Parachutes for stopping high speed vehicles at Bonneville do not have an opening in the center of the chute (at least mine don't). The ribbons start immediately. Bob Stroud, who is one of only three parachute manufacturers for wheel driven vehicles in the U.S., made the parachutes. He has literally made thousands of chutes for racers all over the world. I do believe that he has a little experience in this area. As the parachute has an SFI certification, The parachute cannot be modified to any extent. Only lengths of tethers are allowed to assist the streaming of the chute.

The three premier chute manufactures for protective equipment, which include safety harnesses and firesuits etc., are Deist, Simpson, and Stroud.

The problem with parachutes on wheel driven vehicles at Bonneville is that when the car or motorcycle penetrates the air a vortex is formed which crosses paths at some point behind the vehicle, much like your Amanda going through the water forms a wake which crosses at the rear. This is the area of extreme turbulence for car and motorcycle streamliners. This turbulent area varies in distance from the vehicle as it slows down. Each vehicle is different. Hence, tuning of the chute is important and necessary in most cases.

I watched a program the other day on NASA parachutes. They were having the same problem as I have experienced, i.e., a dancing parachute. You would think that with the multi-billion dollar budget they have, they could build a parachute that would work right out of the box. It was not the case. After several experimentations with the parachute, the final problem solving solution was choking down the outer diameter of the chute, thereby elongating the concave area.