There are "stock" programs that come with the predator and all sorts of parameters you can adjust... only up to 14psi, though.

say you are running 18 or something like that and have to get a custom file. Can the user still tweak all the parameters or are they now locked into the settings of the custom program? In other words, if I have a custom file and I still want to adjust shift points, timing, fuel, tire size, etc., can I still tweak them even though I am not using the "stock" settings in the predator any more?

 

Yes, you can still make the parameter changes with a custom tune/program.