A friend of mine has a GTP and ran a 14.4 w/ only cat-back exhaust.

His first time at the track too. Another friend has one with 3.4 pulley, i/e, shift kit, tranny cooler and ran a 13.8. Needless to say, they are beasts. Even better sleepers than a SVTC. Only thing is they are about as common as air!
-Neal