SAT 1670 for an ESL, is it ok?

Well, I'm an ESL, have been living in the US for 5 yrs now. I got 1480 on my last SAT and 1670 this time, that's like almost 200 pts higher than my last test ^^ Do u think this score is impressive enough for an ESL to go to Davis or other good UCs? However, I still wanna raise my score to 1800+ if possible, how can I improve my score? I tried to study the SAT books and do practice tests, but I dun have enough time and I get bored when I start reading those books...Can anyone gimme any advice? Thx