I would like to start off by saying I have never heard the piece your playing. First, the less tension you have in your hand/arm/shoulder/etc., the faster, more powerful, and better you can play a passage. If you are playing fast, you cannot play with your fingers lifting high off the keyboard. They should be curved. 1.Try separating the parts into smaller 1 beat groups and practice slowly. 2. Try practice long-short-long, short-short-long, etc. All different rhythms. 3. Make sure you are playing deep into the key for each note you hit. 4. Practice slowly concentrated hand alone so that you watch absolutely every note the left hand slowly and firmly hits. In general for speed, it really helps if you can practice everyday, just like anything else. Hopefully I could help:)