EXCLUSIVE

Paul Walker survived the impact of the crash that took his life but suffered horrifically as he was burned alive ... this according to a wrongful death lawsuit his daughter has filed against Porsche.

According to the lawsuit -- obtained by TMZ -- lawyers for 16-year-old Meadow Walker claim when the Porsche Carrera GT crashed and broke apart, Paul's seat belt "snapped Walker's torso back with thousands of pounds of force, thereby breaking his ribs and pelvis," and trapping him in the passenger seat.

The suit claims the fire didn't erupt for 1 minute and 20 seconds after impact, but Paul was helplessly trapped. When the fire broke out, Paul was still alive. The suit alleges, "Paul Walker breathed soot into his trachea while the Porsche Carrera GT burned."

Law enforcement said the cause of the crash was speeding -- 80 to 93 MPH -- at the hands of driver Roger Rodas. But the lawsuit says Rodas was only going between 63 and 71 MPH when it careened out of control. And the suit alleges the car would never have careened if it had a proper stabilization system.

Meadow's lawyers claim Porsche knew the Carrera GT had "a history of instability and control issues."

Meadow's lawyers say the defect could have been corrected with a Porsche Stability Management System (PSM), which prevents swerving. They say the company intentionally decided not to install PSMs in the Carrera GT, even though it was standard in many other models.

The suit raises other issues with the car, including claims there were deficient side door reinforcements and fuel lines that did not adequately protect the car from erupting in flames.

Meadow's lawyer, Jeff Milam, tells TMZ, "The bottom line is that the Porsche Carrera GT is a dangerous car. It doesn't belong on the street. And we shouldn't be without Paul Walker or his friend, Roger Rodas."

The wrongful death lawsuit does not put a figure on damages.