I'm betting an intake and exhaust on the ST should drop it close to another half second. My stock '93 Eclipse GSX ran 15.7s in stock trim at 5800ft (high 14s at sea level) and with just an HKS intake and 2.5" exhaust turned a 15.1 which set me right up with a Z28 of the same vintage. Can't wait to see how the mods respond on the ST.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch