Besides what Herra suggested to improve the speed feel, theres also another possibility as far as I ca think:
What gives the illusion of speed is the "flybys" trough objects, be that an asteroid, a capital ship, or something rly small. The main focus of things should b on those very small objects, cause you arent always on an asteroid field, or flying by a capital ship.
See those tiny floating debris on FS2? The ones that are all around? make them more noticeable when your flying, and the illusion of speed will be pumped up
But yeah, unfortunatly a FS2 ship speed aint that great... the best thing would be a really balanced velocity modifier (turn the game units to their double perhaps, but not on everything or its all broken...). If any1 played those velocity mods made a long time ago, they know what im talking about, but those would need more balanced, and would have to b coded, not tabled, in order to not generate conflicts with the various projects around