Bajengua:
Problem: How can I make my robot Faster?
As you have not told us how fast t is now, that is a bit difficult.
Or, put another way, you need to make your question a lot more specific - what part of your program is working too slowly?
Post your program and tell us all about the hardware that is used in your robot. Post links to datasheets for anything we are unlikely to be familiar with.
...R