He was renowned as an opinionated character who "was about as good as there ever was on engines," according to Marvin Panch, who drove stock cars for Yunick and won the 1961 Daytona 500.

His trademark white uniform and battered cowboy hat, together with a cigar or corncob pipe, were a familiar sight in the pits of almost every NASCAR or Indianapolis 500 race for over twenty years.

This, however, allowed him to exercise his talents for improvising and optimizing mechanical solutions, for example, constructing a tractor from the remains of a junked car.

As stated in a New York Times article, Yunick claimed that he joined the Army Air Corps in 1941 and piloted a B-17 Flying Fortress named "Smokey and his Firemen" on more than 50 missions over Europe.

[1] Official military records from the National Archives reflect that Yunick was drafted from civilian life as a welder in January 1943, at the age of 19 in Philadelphia at the enlisted rank of Private.

[6] In 1946, Yunick married and moved to Daytona Beach, Florida, because "it was warm and looked good" when he had flown over it on training missions.

He prepared a Hudson Hornet for driver Herb Thomas for the second running of the Southern 500 in Darlington, South Carolina, which won the race.

The wing, designed to increase downforce, allowed Rathmann to reach cornering speeds never before seen at the Indianapolis Motor Speedway but created so much drag that it caused the car to record slower lap times.

The United States Automobile Club (USAC) immediately banned the use of wings, but they soon began to appear on cars competing in Can-Am and Formula One.

Following Fireball Roberts' 1964 crash at Charlotte — where after 40 days in pain from burns, he died — Yunick began a campaign for safety modifications to prevent a repeat of such disasters.

Yunick also used such innovations as offset chassis, raised floors, roof spoilers, nitrous oxide injection, and other modifications, often within the letter of the rule book, if not the spirit.

In another incident, Yunick showed up for a race with stock fender wells still installed on his Chevelle, even though the rules stated they could be removed.

The shoulder harness was modified to include a cable-ratchet mechanism from a military helicopter to give the driver enough freedom of movement.

Contrary to popular opinion, Yunick designed the first "safe wall" racetrack barrier in the early 1980s using old tires between sheets of plywood, but NASCAR did not adopt his idea.

Some of his items, including hats, pipes, boots, engines, etc., are on display (loaned from family, most of them) at museums, from racetracks to the Smithsonian (history of racing).

He also wrote for Circle Track magazine and published his autobiography Best Damn Garage in Town...The World According to Smokey in July 2001.

Instead, he preferred that his tools, equipment, cars, engines, and parts go to people who would use them, and before his death, he undertook to restore as much of it as possible to working conditions.