not trying to be an a**, but before someone else says it i'll say it, search button goes a long way lol here's an old thread with sound clips. as far as hp gains..according to ebay:
7.8 hp and 4.5 lb-ft of torque increase at the front wheels (V6 models)
8.0 hp and 7.1 lb-ft of torque increase at the front wheels (4-cylinder models)
finally-got-a-couple-sound-clips-of-my- ... 71369.html