Fast 5 is widely acknowledged as the pivotal moment when the Fast & Furious franchise finally lost its grip on the boundaries of physics and became completely outrageous, but the truth is that the saga was always silly. Much has changed since the original 2001 movie. But, while Fast & Furious' focus may have shifted from underground LA street racing to firing Ludacris and Tyrese into space, each movie has stuck to the series' principles of full-throttle action at the expense of realism. Although Fast 5 and the notorious safe chase are often blamed for the departure into fantasy, there are many earlier moments that prove how ridiculous the series has always been.

https://screenrant.com/ridiculous-fast-and-furious-moments-before-fast-five/