PHILADELPHIA — There are two kinds of roars that echo off Franklin Field’s venerable brick walls during the Penn Relays, and resonate on for years afterward. The more famous of them is the “Wooooo!” that rises in the final meters of a race, encouraging the chaser and warning the chased as they race toward the finish line. The other is the thunderclap that erupts when a track star is introduced by the public-address announcer to the masses in the stands. From Marion Jones to Justin Gatlin, Usain Bolt to Shelly-Ann Fraser-Pryce, the names and the noises are as big as they come. On Saturday, a ne…