I had a 180 PSAT score and i ended up achieving a superscored SAT score of 2130.
My first score was 2050, and I began to regularly tutor for SAT Math, which boosted my math score from 640 to 720.
The secret is to do problem, after problem, after problem, after problem… Obsession. Pretty much the secret to be exceptional at anything, I believe.
-You have to focus completely and eliminate all distractions. Go to the answer sections of your SAT books for Math and Reading as well and look at the how they interpret the answers.
-Don’t begin to time yourself too quickly, just go easy on your brain at first and try to figure out how to understand SAT-type questions and reason out the answer.
-You will soon figure out if you keep a steady obsession with doing well on the SAT that a lot of the questions are structured in a similar way. Once you reach this point you will know how to work your way around the problem by getting in the head of the person who wrote the problem in the first place.
But all this takes lots of dedication and reading and doing lots of problems.
-I used Princeton and College Board.
-Also for the vocab, focus on learning prefixes and suffixes and not so much memorizing the words. you will find that it is more handy to put together the definition of a random word using pre/suffixes than just wasting time learning 1000 words for a total of like 25 vocabulary words on a single exam.
-Lastly, if you are not focusing while you are studying, then you are wasting your time. You need to constantly be processing the information at this rate. If you notice you are too tired, get some sleep and concentrate the next day.
I think it’s possible to improve as much as you want but your goal will take lots of work. However, I was able to improve 300+ points, if I could, certainly you can as well and MUCH higher than that. 
Hope that helps.