Rattling noise when the 8 gets warm

I have a 2005 rx8 with around 111,000 miles and it runs great, starts decently, pulls hard and sounds very clean untill I drive it for around 15-20 mins then it loses throttle response badly along with its acceleration and when you lay into it it makes a raspy rattling noise.. Just pulled out the ssv and cleaned that but it didn't change the problem at all .. Any ideas??? I made a video of it in action also the first clip is when it's cool yet and how it should sound (does have a cold air intake so most of the sound is coming from that)

http://ift.tt/1Cs97t6