Port engine turbo turning up slower than starboard

Recently you noticed? New symptom or always been there? How long has it been noticed and how is your hull bottom?
Even with the new fancy stuff, the slave is chasing the master. How clean & strong everything is can help it seem effortless or a lil late. Replacing the fuel filters may have helped the strong part. When was the last diver under da boat?
When at cruising, does your engine data match? All Air pressures, fuel pressures, boost and pyro (if you have Pyro). I think Skippy J was trying to ask some of these engine comparisons also.

His common rail MAN's are done through the computer, so there is very little if any noticable lag between the motors when on sync. The computer pretty much sends throttle position to both at virtually the same time.

Yeah and you're right there is a decent delay in the Glenndenning and it also does put a lot more stress/load on the master engine. It is better for the engines to bring it up to plane on both throttles and then switch it on.