Slow to rev to 6k rpm

[red s13]

I uped the boost from 4psi to 6psi and the car feels good, but once I get up to about 5k rpm it feels like the car hesitates to get to 6k rpms. Do you guys think it could be my plug gap? Its gaped at .28 right now.

[C-Kwik]

If it feels like you hit a rev limiter, then it might be a spar issue. Though you are running a very narrow gap already. You might want to make sure your coil is in good shape. Higher RPM allows less time for the coil to be saturated and if there is not enough juice, the spark won't occur. 0.28" gap should not be an issue with a ignition system that is in good working order at only 6 psi of boost.