for whatever reason, my ffshifter doesnt work with mostly GTR cars, i havent tried anymore. they work perfectly for the rb4, xrt, all the upper cars, but the GTRs and the formula 1s.

does anyone know why?

The FXR, XRR and the formula cars now all need a sequential shifter as they have a sequential gearbox. A shifter in H-gate mode does not work with them any more. Basically you have to reconfigure it for these cars (via a script) to make your joystick's forward-movement a downshift and the backward-movement an upshift (or the other way round if you're a pansy ).

Script Guide

aw man, do you think its possible to make it so that my shifting on the ffshift registers as a up/downshift?

IE: going from 1st to 2nd on my ffshifter would just be like a sequential shifter, or going from 4th down all the way to 2nd would be 2 downshifts?

thats a shame, i was kind looking forward to shifting on high powered cars with my ffshifter

You just have to rebind the buttons within LFS (which you can do using scripts). Right now you use some external program to make a certain joystick position report as a button press, no? In LFS, you have these button presses assigned to "First", "Second", etc., but you have to change the assignment for 3rd and 4th to "Shift down" and "Shift up" respectively.

As Android said, you can use scripts to dynamically change the binding of controls (among other things) to have the controls automatically change from one car to another. I must admit, though, that I miss having a gated shifter in the XRR, but the devs have spoken.

If you're using Ghostve's FFShifter soft, there's a sequential mode in it which translate gear change into keypresses, it works well and it should be exactly what you're looking for.