The only way to raise the rev limiter is:
Reprogrammed ECU (Hondata)
But a Hondata program isn't a direct swap for a F23 motor, so there's some modification that'll be needed
OR
Engine swap...Dropping in a motor (H22/H23) with a higher rev limiter
But honestly, Isn't 6800RPM's enough.
Oh, wait, you have a SE which only comes with an automatic tranny. So you redline at 6,250RPMs