This is a very disturbing post unless you are talking about hookah.
From what I know about pumps and motors in general, I doubt you're in luck. Do you need more pressure or volume? If you just want to add a person and go no deeper you just need more volume. If you want to go deeper you need both. Running a
compressor faster does not increase pressure, so adding a faster
motor doesn't help deeper and the
compressor is probably only rated for a certain speed anyway. A higher pressure compressor will require more
power, so you replace both the
motor and compressor and now you're at the point where you're at
buying the next one up.