Pitbull's legal war with Lindsay Lohan is getting straight up nasty — 'cause now, the rapper's filed new legal docs calling out LiLo for being a liar with a rap sheet longer than her movie credits.

Pit just filed a response to Lindsay's "Give Me Everything" lawsuit — in which she claims the hip hop star owes her money for using her name in the song … when he rapped, "I got it locked up like Lindsay Lohan."

Lohan filed the original suit in NY State Court, stating she was a resident of Nassau County — but Pit is calling B.S., claiming she's been living in California since 2004 … and "given her frequent legal troubles, Ms. Lohan possesses irrevocable ties to California that are likely to keep her there for the foreseeable future."

Then, Pit spells out why she's full of crap, every single one of her legal problems in California including her multiple stints in the slammer, the house arrest, her problems at the Downtown Women's Center and all of the community service she's required to complete in the Golden State in the near future.

Pit concludes, "Thus, in light of Ms. Lohan's continuing obligations to the State of California, as well as the foregoing facts, Ms. Lohan is a citizen of California, not New York."

Pit wants the case transferred out of NY State court and into federal court — where he thinks he'll have a better shot of taking Lohan down.