This is an IPS patch you can apply to your CF ROM in order to alter the steering from pseudo-analogue to linear fixed rate.
Use LunarIPS or your own personal favourite IPS util to apply the patch file to your CF ROM.
Some further words from Cyrano Jones at AtariAge:
The problem [with Checkered Flag] is you don’t actually control the car, you control the camera – so its a given that you are never going to have a great driving experience with that.
Also, no point in adding rotary support, the frame rate is so low the controls will feel disconnected (yeah.. I know…)
It’s possible to adjust the turn rate – let me know if you think it should be more or less than I currently have it set to and I’ll see what can be done.
I picked something in the middle range which seemed to give the best (of the admittedly still quite bad) results.
Just remember, if you are making a cart out of this patch, you also need to strip the first 8k off it and add the universal cart header, or it will fail the checksum test and redscreen.