I don t have an F1but things to usually check for are:
– binding in the front wheels, wheel nuts could be too tight on one side or the other. Spin them to see if they are free. Clean & flush bearings out with some electric motor spray or wd40
– chassis tweak, place mini-z on flat surface, use an hobby knife to lift the rear up and see if both tyres lift off the ground at the same time, if not, the chassis is tweaked.
– Ensure that ball diff doesn’t bind by cleaning and lubricating with some silicon grease.
– Make sure front king pins don’t bind when compressed. Polish them up if they do.
– Good set of tyres for the surface that you’re running on.