If you lack the raw speed to compete with more experienced players, you should focus on lines and br techniques.
On wipeoutrankings.com you can find a TT guide for every track and the porobably most important speed, Phantom. In general, there are lots of useful videos included, which can help you to improve your speed.
Note, that you won't keep up with the listed times - this is due to the gane mechanics. The important thing is to be able to copy the shown techniques, as far as possible.
To know, whats theoretically possible, is imo the only option to reach a higher level.
Good luck!