First lobe vtec... not to lecture but there is only one vtec x-over at 4400rpms in a stock gsr, 5800rpms is the secondaries in the intake manifold opening. For "surges" like that I would maybe look into the fuel system. My power band felt like it was sugring due to a bad fuel curve. What kind of mods do you have? Are you running a vafc? Are you throwing any codes?