jo ich hab mich mal nen bissl damit beschäftigt, weil mir das mit gamepad mehr fetz macht.
es gibt nen xbox controller emulator der mit nem mod auch vibration support, vorher ist das einfach immer abgestürzt.
einfachd as ganze gerassel ins gta iv verzeichnis entpacken und los gehts.
mit der xinputtest.exe könnt ihr die funktionalität testen... 
die config:
Code
[Options]
UseAutoPad=0 #use 0 to 1; automatically make other PAD to PAD1 after detecting movement
UseInitBeep=1 #use 0 to 1; default 1; beep on init
#Logitech Cordless Rumblepad 2 / Generic Rumble Controller
[PAD1]
Index=0 #controller index in game controllers list; 0 is first; -1 to ignore this pad
Left Analog X=1 #axis index; use - to invert; precede with 's' for a slider eg; s-1; 7 to disable
Left Analog Y=-2 #axis index; use - to invert; precede with 's' for a slider eg; s-1; 7 to disable
Right Analog X=3 #axis index; use - to invert; precede with 's' for a slider eg; s-1; 7 to disable
Right Analog Y=-6 #axis index; use - to invert; precede with 's' for a slider eg; s-1; 7 to disable
Left Analog X Linear=0 #-100 to +100 raise this number to increase sensitivity near center
Left Analog Y Linear=0 #-100 to +100 raise this number to increase sensitivity near center
Right Analog X Linear=0 #-100 to +100 raise this number to increase sensitivity near center
Right Analog Y Linear=0 #-100 to +100 raise this number to increase sensitivity near center
Left Analog X+ Button=0 #button id; 0 to disable
Left Analog X- Button=0 #button id; 0 to disable
Left Analog Y+ Button=0 #button id; 0 to disable
Left Analog Y- Button=0 #button id; 0 to disable
Right Analog X+ Button=0 #button id; 0 to disable
Right Analog X- Button=0 #button id; 0 to disable
Right Analog Y+ Button=0 #button id; 0 to disable
Right Analog Y- Button=0 #button id; 0 to disable
D-pad POV=1 #POV index; 0 to disable
D-pad Up=0 #button id; 0 to disable
D-pad Down=0 #button id; 0 to disable
D-pad Left=0 #button id; 0 to disable
D-pad Right=0 #button id; 0 to disable
A=2 #button id; 0 to disable
B=3 #button id; 0 to disable
X=1 #button id; 0 to disable
Y=4 #button id; 0 to disable
Left Shoulder=5 #button id; 0 to disable
Right Shoulder=6 #button id; 0 to disable
Back=9 #button id; 0 to disable
Start=10 #button id; 0 to disable
Left Thumb=11 #button id; 0 to disable
Right Thumb=12 #button id; 0 to disable
Left Trigger=7 #button id; precede with 'a' for an axis; eg; a-6; for a slider precede with 's' eg; s-1
Right Trigger=8 #button id; precede with 'a' for an axis; eg; a-6; for a slider precede with 's' eg; s-1
UseForceFeedback=1 #use 0 to 1; default 0
ForceLargeGain=10000 #use 0 to 10000; default 10000; effect intensity
ForceLargePeriod=120000 #use 0 to 200000; default 120000; effect frequency; wheel only
ForceLargeFadeTime=10 #use 0 to 100; default 10
ForceLargeFadeIn=0 #use 0 to 1; default 1
ForceLargeFadeOut=0 #use 0 to 1; default 1
ForceLargeStartMag=0 #use 0 to 10000; default 2000; effect will begin with this value
ForceSmallGain=10000 #use 0 to 10000; default 10000; effect intensity
ForceSmallPeriod=30000 #use 0 to 200000; default 30000; effect frequency; wheel only
ForceSmallFadeTime=10 #use 0 to 100 default 10
ForceSmallFadeIn=0 #use 0 to 1; default 1
ForceSmallFadeOut=0 #use 0 to 1; default 1
ForceSmallStartMag=0 #use 0 to 10000; default 2000; effect will begin with this value
WheelInertiaGain=2500 #use 0 to 10000; default 2500; effect intensity; wheel only
WheelSpringGain=5000 #use 0 to 10000; default 5000; effect intensity; wheel only
SteeringWheel=0 #use 0 to 1; enable for all wheel effects
ForcePercent=100 #use 0 to 100; default 100und die files im anhang