I am not sure how exactly your supporter fan base works for you club/country but if this has not been done already maybe you should consider a leader of some sort? to direct the fans in certan chants, movements, songs?
In this match you can see and hear person on a micraphon after 1:30 in the video shouting instructions of chants, songs, movements to the fans almost like army. This really helps organize and sync chants as well as encourage fans to keep supporting the team. Players run for 90 minuts, we shall sing and chant for 90 minutes :)
I believe city fans can become the most intimidating, entertaning fans in the premeir league.
Im sorry if you guys already use this suggestion with the micraphone, like ive said I am not knowing how you guys organize yourselves so I do not know if you have used micrahone or not. If not just an idea ;)
[youtube]http://www.youtube.com/watch?v=6R5mtCkStMU&feature=related[/youtube]