How are your motor temps with this setup? Are you running the overdrive pulley up front? What size is your track?

I am running a Team Epid D3 4.5 Turn 550 Motor and I have more motor than I could ever put down. Very happy with the power and feel no need for more. I am geared at a 62/15 and may go to a 16 if I can keep the temps down. I have found that you need to drop 1-2 teeth on the pinion if you are running the front overdrive pulley. I would think you would gear a 5.5 at least a 62/15 and that should wake it up, I would not be suprised if you ended up at a 16 or 17 depending on track size.