He decided to end his racing career in 1977, because he started to think about a telephone call that he needed to make while he was practicing at Indianapolis Motor Speedway.

"[1] Simpson's uncle owned a military surplus store, and suggested that he use a cross-form parachute to slow down the drag car.

They tested it by attaching it to a tow hitch, and dumping it from the back of the Chevy wagon while Sorokin drove down a street at 100 mph.

[1] Simpson had developed over 200 racing safety products, including three generations of fire suits.

[4][5][6] Simpson Performance Products was involved in a controversy after the February 2001 death of Dale Earnhardt over whether the seat belt manufactured by the company had malfunctioned.

[4][6] NASCAR's initial investigation into the crash in part blamed seat belt failure;[4] eventually the series moved to institute long called for safety standards, such as mandated use of the HANS device.

[4] Simpson sued NASCAR for $8.5 million defamation of character suit in February 2003,[4][6] later withdrawing it after receiving an undisclosed settlement.

In addition to the drag chutes and Nomex underwear that Bill Simpson first introduced to racing, Impact!