It appears that I will be making the unpopular comment here, but you should leave. First, you need to get rid of this "but we are friends" mentality. You are a group of people with supposedly similar goals, but it has become apparent to you that this isn't the case (if you did truly have similar goals the other members of your group would be putting out similar dps). There are plenty of hardcore guilds out there who have been bleeding members and would love to have a dedicated member who cares enough to put forth the minimal effort required to be a successful raider. I knew a guy recently who applied to a HC guild one morning, got accepted, server transferred and was raiding ICC hard modes that evening.

There is nothing wrong with setting your raiding goals and expecting to meet them. If your "friends" are unwilling to spend the five minutes that it takes to make sure they have the right spec and rotation to get their dps up to your level, there is nothing wrong with saying "I am going to leave and raid with people who put forth the same effort that I do." If these people are actually your "friends" they will support you and you will still get to spend time with them and run 5 mans together and do all that happy funtime stuff you always did... or you won't but at least then you would know how much they truly cared.