I couldn't keep up with the 600's on my 1996 Fireblade at Donington since the new ones make more power and weigh less.
I couildn't keep up with the F3 NSR's either, since their corner speed was so high that it took a whole straight for me to build up to the same speed as they exited the previous corner!
Could you lose a few pounds? Most of us could, and they're free!
Better brakes and suspension will knock more off your lap times than all the performance hikes in the world, as you feel more confident and therefore carry more corner speed onto the straights.
Last idea is to pick tracks with lots of corners and no long straights!