Warrior dps help on Magaera

So whats the trick to this fight. I'm not doing adds just on boss full time. I tried staggering my CDs so they line up with execute, so I would pop all at 25% this would give around 17 secs till head is dead. I tried chaining CDs, so use them when they come up. Sometimes i get lucky and at 140k dps. But most of the time hover around 120k.

For our raids dps execute phases last around 12secs.

Link to profile
http://us.battle.net/wow/en/characte.../galvin/simple

Forgot to mention this is heroic 25man.