Your sentance that I have highlighted in bold is completely wrong I'm afraid, and this could be why you are getting the results you currently are.
The film chosen will have a certain contrast when exposed and developed in a particular way, any variation from that and there will be marked differences in the negative.
Under normal development and in the same lighting Tri X would have much less contrast than FP4 or Pan F, with Pan F having the most contrast.
In order for you to get Tri X to have a lot of contrast you must be either over developing the negatives (blocking up the dark tones) or over exposing the film (but probably a combination of both) and thus compressing the tonal range, and printing on grades 4 + 5 will only exacerbate that further.
From the tone of your posts though you are happy with the end result and that is all that really matters, but your being happy with how you process and print your negatives does not mean that it is the correct way, but many a 'style' has been developed from a specific and repeatable change to what would be considered normal.
Another way of introducing higher contrast in monochromatic images is to use a filter on the lens at the time of shoorting, typically an Orange or Red with a very dark Red giving some extremely high contrast and almost IR in feel.
As for your sentance that I have highlighted in bold/dark red, know you are getting close to understanding how exposure x development can be used to create a full toned negative that will print well on standard grade paper.
This is the first steps in really understanding how the Zone System works.