(FORTUNE Magazine) – Ed McCabe left the familiar rat race only to get into races of an even more brutal sort. Three years ago the legendary adman -- perhaps most famous for his ''It takes a tough man to make a tender chicken'' campaign for Frank Perdue -- abandoned the Scali McCabe Sloves agency he had co-founded. A year later he entered the grueling Paris-Dakar auto rally, only to run out of gas in the middle of the Sahara desert. McCabe came home to write ads for the presidential campaign of Michael Dukakis -- they were rejected as too negative -- and then wrote a book about the Paris-Dakar race, Against Gravity, which comes out this month. McCabe, 51, is now back in the ad business. He's a partner at Miami's Beber Silverstein, one of the few agencies run by women. Says he: ''I missed the major commitment to a single thing.''