Change port range for home-made device

[CXN2615]

I take a pedal to use as throttle, it's own chip was broken so I wired it's port to an used joystick, but I find that it digitally only use 90 degree of 270 range (even in calibration mode with raw data shown), it seems to be made to match it's original joystick usage. But my pedal will use about 180 degree, so I got half deadzone. I tryed to change port, seriesly or parallelly add some resistance, use windowes's own driver rather that joystick's factory one... They all not work. In some way, I can make the "digital-range" only move half with 90d rotate, but it stops there as I futher push my pedal
Is there anyway to add it's range to anything above 180? (then I can trim it down to 180 anyway)