diff --git a/dist/idac/segatools.ini b/dist/idac/segatools.ini
index 830f78b..bf9bafc 100644
--- a/dist/idac/segatools.ini
+++ b/dist/idac/segatools.ini
@@ -29,7 +29,7 @@ enable=1
 ; If you disable netenv then you must set this to your LAN's IP subnet, and
 ; that subnet must start with 192.168. Set it to your LAN's subnet if you 
 ; want to play head-to-head using netenv=1.
-subnet=192.168.100.0
+subnet=192.168.158.0
 
 ; Override the keychip's region code. Most games seem to pay attention to the
 ; DS EEPROM region code and not the keychip region code, and this seems to be
@@ -174,3 +174,8 @@ gear6=18
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30
diff --git a/dist/idz/segatools.ini b/dist/idz/segatools.ini
index c7fa88b..e7b0701 100644
--- a/dist/idz/segatools.ini
+++ b/dist/idz/segatools.ini
@@ -173,3 +173,8 @@ gear6=18
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30
diff --git a/dist/swdc/segatools.ini b/dist/swdc/segatools.ini
index f3867a7..fb93e50 100644
--- a/dist/swdc/segatools.ini
+++ b/dist/swdc/segatools.ini
@@ -133,3 +133,8 @@ wheelGreen=10
 ; (Needed when using DirectInput for the Dualshock 4 for example)
 reverseAccelAxis=0
 reverseBrakeAxis=0
+
+; Force feedback settings.
+; Strength of the force feedback spring effect in percent. Possible values
+; are 0-100.
+centerSpringStrength=30
diff --git a/idacio/config.c b/idacio/config.c
index f6ed605..2daeb8f 100644
--- a/idacio/config.c
+++ b/idacio/config.c
@@ -79,6 +79,14 @@ void idac_di_config_load(struct idac_di_config *cfg, const wchar_t *filename)
         cfg->gear[i] = GetPrivateProfileIntW(L"dinput", key, i + 1, filename);
     }
 
+    // FFB configuration
+
+    cfg->center_spring_strength = GetPrivateProfileIntW(
+                            L"dinput",
+                            L"centerSpringStrength",
+                            30,
+                            filename);
+
 }
 
 void idac_xi_config_load(struct idac_xi_config *cfg, const wchar_t *filename)
diff --git a/idacio/config.h b/idacio/config.h
index ec91ce6..bbf568d 100644
--- a/idacio/config.h
+++ b/idacio/config.h
@@ -23,6 +23,9 @@ struct idac_di_config {
     uint8_t gear[6];
     bool reverse_brake_axis;
     bool reverse_accel_axis;
+
+    // FFB configuration
+    uint16_t center_spring_strength;
 };
 
 struct idac_xi_config {
diff --git a/idacio/di-dev.c b/idacio/di-dev.c
index c77584b..62cab2f 100644
--- a/idacio/di-dev.c
+++ b/idacio/di-dev.c
@@ -44,7 +44,8 @@ HRESULT idac_di_dev_start(IDirectInputDevice8W *dev, HWND wnd)
     return hr;
 }
 
-void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
+void idac_di_dev_start_fx(
+    IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength)
 {
     /* Set up force-feedback on devices that support it. This is just a stub
        for the time being, since we don't yet know how the serial port force
@@ -67,7 +68,7 @@ void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     DWORD axis;
     LONG direction;
     DIEFFECT fx;
-    DICONSTANTFORCE cf;
+    DICONDITION cond;
     HRESULT hr;
 
     assert(dev != NULL);
@@ -77,11 +78,17 @@ void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     dprintf("DirectInput: Starting force feedback (may take a sec)\n");
 
+    // Auto-centering effect
     axis = DIJOFS_X;
     direction = 0;
 
-    memset(&cf, 0, sizeof(cf));
-    cf.lMagnitude = 0;
+    memset(&cond, 0, sizeof(cond));
+    cond.lOffset = 0;
+    cond.lPositiveCoefficient = strength;
+    cond.lNegativeCoefficient = strength;
+    cond.dwPositiveSaturation = strength; // For FG920?
+    cond.dwNegativeSaturation = strength; // For FG920?
+    cond.lDeadBand = 0;
 
     memset(&fx, 0, sizeof(fx));
     fx.dwSize = sizeof(fx);
@@ -93,20 +100,19 @@ void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     fx.cAxes = 1;
     fx.rgdwAxes = &axis;
     fx.rglDirection = &direction;
-    fx.cbTypeSpecificParams = sizeof(cf);
-    fx.lpvTypeSpecificParams = &cf;
+    fx.cbTypeSpecificParams = sizeof(cond);
+    fx.lpvTypeSpecificParams = &cond;
 
     hr = IDirectInputDevice8_CreateEffect(
             dev,
-            &GUID_ConstantForce,
+            &GUID_Spring,
             &fx,
             &obj,
             NULL);
 
     if (FAILED(hr)) {
-        dprintf("DirectInput: DirectInput force feedback unavailable: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback unavailable: %08x\n",
                 (int) hr);
-
         return;
     }
 
@@ -114,15 +120,15 @@ void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     if (FAILED(hr)) {
         IDirectInputEffect_Release(obj);
-        dprintf("DirectInput: DirectInput force feedback start failed: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback start failed: %08x\n",
                 (int) hr);
-
         return;
     }
 
     *out = obj;
 
-    dprintf("DirectInput: Force feedback initialized and set to zero\n");
+    dprintf("DirectInput: Centering spring effects initialized with strength %d%%\n", 
+            strength / 100);
 }
 
 HRESULT idac_di_dev_poll(
diff --git a/idacio/di-dev.h b/idacio/di-dev.h
index efbe39e..b1559e3 100644
--- a/idacio/di-dev.h
+++ b/idacio/di-dev.h
@@ -11,7 +11,7 @@ union idac_di_state {
 };
 
 HRESULT idac_di_dev_start(IDirectInputDevice8W *dev, HWND wnd);
-void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out);
+void idac_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength);
 HRESULT idac_di_dev_poll(
         IDirectInputDevice8W *dev,
         HWND wnd,
diff --git a/idacio/di.c b/idacio/di.c
index 75e2c50..55018e8 100644
--- a/idacio/di.c
+++ b/idacio/di.c
@@ -75,6 +75,7 @@ static uint8_t idac_di_gear[6];
 static bool idac_di_use_pedals;
 static bool idac_di_reverse_brake_axis;
 static bool idac_di_reverse_accel_axis;
+static uint16_t idac_di_center_spring_strength;
 
 HRESULT idac_di_init(
         const struct idac_di_config *cfg,
@@ -173,7 +174,9 @@ HRESULT idac_di_init(
         return hr;
     }
 
-    idac_di_dev_start_fx(idac_di_dev, &idac_di_fx);
+    // Convert the strength from 0-100 to 0-10000 for DirectInput
+    idac_di_dev_start_fx(idac_di_dev, &idac_di_fx, 
+                         idac_di_center_spring_strength * 100);
 
     if (cfg->pedals_name[0] != L'\0') {
         hr = IDirectInput8_EnumDevices(
@@ -364,6 +367,16 @@ static HRESULT idac_di_config_apply(const struct idac_di_config *cfg)
         idac_di_gear[i] = cfg->gear[i];
     }
 
+    // FFB configuration
+
+    if (cfg->center_spring_strength < 0 || cfg->center_spring_strength > 100) {
+        dprintf("Wheel: Invalid center spring strength: %i\n", cfg->center_spring_strength);
+
+        return E_INVALIDARG;
+    }
+
+    idac_di_center_spring_strength = cfg->center_spring_strength;
+
     return S_OK;
 }
 
diff --git a/idzio/config.c b/idzio/config.c
index 25b188d..2a6e083 100644
--- a/idzio/config.c
+++ b/idzio/config.c
@@ -76,7 +76,14 @@ void idz_di_config_load(struct idz_di_config *cfg, const wchar_t *filename)
         swprintf_s(key, _countof(key), L"gear%i", i + 1);
         cfg->gear[i] = GetPrivateProfileIntW(L"dinput", key, i + 1, filename);
     }
+    
+    // FFB configuration
 
+    cfg->center_spring_strength = GetPrivateProfileIntW(
+                            L"dinput",
+                            L"centerSpringStrength",
+                            30,
+                            filename);
 }
 
 void idz_xi_config_load(struct idz_xi_config *cfg, const wchar_t *filename)
diff --git a/idzio/config.h b/idzio/config.h
index 6b4cd20..155f797 100644
--- a/idzio/config.h
+++ b/idzio/config.h
@@ -21,6 +21,9 @@ struct idz_di_config {
     uint8_t gear[6];
     bool reverse_brake_axis;
     bool reverse_accel_axis;
+
+    // FFB configuration
+    uint16_t center_spring_strength;
 };
 
 struct idz_xi_config {
diff --git a/idzio/di-dev.c b/idzio/di-dev.c
index 6f66bf0..26cf6e3 100644
--- a/idzio/di-dev.c
+++ b/idzio/di-dev.c
@@ -44,7 +44,8 @@ HRESULT idz_di_dev_start(IDirectInputDevice8W *dev, HWND wnd)
     return hr;
 }
 
-void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
+void idz_di_dev_start_fx(
+    IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength)
 {
     /* Set up force-feedback on devices that support it. This is just a stub
        for the time being, since we don't yet know how the serial port force
@@ -67,7 +68,7 @@ void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     DWORD axis;
     LONG direction;
     DIEFFECT fx;
-    DICONSTANTFORCE cf;
+    DICONDITION cond;
     HRESULT hr;
 
     assert(dev != NULL);
@@ -77,11 +78,17 @@ void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     dprintf("DirectInput: Starting force feedback (may take a sec)\n");
 
+    // Auto-centering effect
     axis = DIJOFS_X;
     direction = 0;
 
-    memset(&cf, 0, sizeof(cf));
-    cf.lMagnitude = 0;
+    memset(&cond, 0, sizeof(cond));
+    cond.lOffset = 0;
+    cond.lPositiveCoefficient = strength;
+    cond.lNegativeCoefficient = strength;
+    cond.dwPositiveSaturation = strength; // For FG920?
+    cond.dwNegativeSaturation = strength; // For FG920?
+    cond.lDeadBand = 0;
 
     memset(&fx, 0, sizeof(fx));
     fx.dwSize = sizeof(fx);
@@ -93,20 +100,19 @@ void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     fx.cAxes = 1;
     fx.rgdwAxes = &axis;
     fx.rglDirection = &direction;
-    fx.cbTypeSpecificParams = sizeof(cf);
-    fx.lpvTypeSpecificParams = &cf;
+    fx.cbTypeSpecificParams = sizeof(cond);
+    fx.lpvTypeSpecificParams = &cond;
 
     hr = IDirectInputDevice8_CreateEffect(
             dev,
-            &GUID_ConstantForce,
+            &GUID_Spring,
             &fx,
             &obj,
             NULL);
 
     if (FAILED(hr)) {
-        dprintf("DirectInput: DirectInput force feedback unavailable: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback unavailable: %08x\n",
                 (int) hr);
-
         return;
     }
 
@@ -114,15 +120,15 @@ void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     if (FAILED(hr)) {
         IDirectInputEffect_Release(obj);
-        dprintf("DirectInput: DirectInput force feedback start failed: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback start failed: %08x\n",
                 (int) hr);
-
         return;
     }
 
     *out = obj;
 
-    dprintf("DirectInput: Force feedback initialized and set to zero\n");
+    dprintf("DirectInput: Centering spring effects initialized with strength %d%%\n", 
+            strength / 100);
 }
 
 HRESULT idz_di_dev_poll(
diff --git a/idzio/di-dev.h b/idzio/di-dev.h
index 9c8b2d2..9b3d03f 100644
--- a/idzio/di-dev.h
+++ b/idzio/di-dev.h
@@ -11,7 +11,7 @@ union idz_di_state {
 };
 
 HRESULT idz_di_dev_start(IDirectInputDevice8W *dev, HWND wnd);
-void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out);
+void idz_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength);
 HRESULT idz_di_dev_poll(
         IDirectInputDevice8W *dev,
         HWND wnd,
diff --git a/idzio/di.c b/idzio/di.c
index 5d0a454..e0cb4c6 100644
--- a/idzio/di.c
+++ b/idzio/di.c
@@ -73,6 +73,7 @@ static uint8_t idz_di_gear[6];
 static bool idz_di_use_pedals;
 static bool idz_di_reverse_brake_axis;
 static bool idz_di_reverse_accel_axis;
+static uint16_t idz_di_center_spring_strength;
 
 HRESULT idz_di_init(
         const struct idz_di_config *cfg,
@@ -171,7 +172,9 @@ HRESULT idz_di_init(
         return hr;
     }
 
-    idz_di_dev_start_fx(idz_di_dev, &idz_di_fx);
+    // Convert the strength from 0-100 to 0-10000 for DirectInput
+    idz_di_dev_start_fx(idz_di_dev, &idz_di_fx, 
+                        idz_di_center_spring_strength * 100);
 
     if (cfg->pedals_name[0] != L'\0') {
         hr = IDirectInput8_EnumDevices(
@@ -346,6 +349,16 @@ static HRESULT idz_di_config_apply(const struct idz_di_config *cfg)
         idz_di_gear[i] = cfg->gear[i];
     }
 
+    // FFB configuration
+
+    if (cfg->center_spring_strength < 0 || cfg->center_spring_strength > 100) {
+        dprintf("Wheel: Invalid center spring strength: %i\n", cfg->center_spring_strength);
+
+        return E_INVALIDARG;
+    }
+
+    idz_di_center_spring_strength = cfg->center_spring_strength;
+
     return S_OK;
 }
 
diff --git a/swdcio/config.c b/swdcio/config.c
index 0dce00e..4208c76 100644
--- a/swdcio/config.c
+++ b/swdcio/config.c
@@ -67,6 +67,14 @@ void swdc_di_config_load(struct swdc_di_config *cfg, const wchar_t *filename)
                             L"reverseAccelAxis",
                             0,
                             filename);
+
+    // FFB configuration
+
+    cfg->center_spring_strength = GetPrivateProfileIntW(
+                            L"dinput",
+                            L"centerSpringStrength",
+                            30,
+                            filename);
 }
 
 void swdc_xi_config_load(struct swdc_xi_config *cfg, const wchar_t *filename)
diff --git a/swdcio/config.h b/swdcio/config.h
index d6f9667..ba3240c 100644
--- a/swdcio/config.h
+++ b/swdcio/config.h
@@ -19,6 +19,9 @@ struct swdc_di_config {
     uint8_t wheel_yellow;
     bool reverse_brake_axis;
     bool reverse_accel_axis;
+
+    // FFB configuration
+    uint16_t center_spring_strength;
 };
 
 struct swdc_xi_config {
diff --git a/swdcio/di-dev.c b/swdcio/di-dev.c
index 116e529..254596a 100644
--- a/swdcio/di-dev.c
+++ b/swdcio/di-dev.c
@@ -44,7 +44,8 @@ HRESULT swdc_di_dev_start(IDirectInputDevice8W *dev, HWND wnd)
     return hr;
 }
 
-void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
+void swdc_di_dev_start_fx(
+    IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength)
 {
     /* Set up force-feedback on devices that support it. This is just a stub
        for the time being, since we don't yet know how the serial port force
@@ -67,7 +68,7 @@ void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     DWORD axis;
     LONG direction;
     DIEFFECT fx;
-    DICONSTANTFORCE cf;
+    DICONDITION cond;
     HRESULT hr;
 
     assert(dev != NULL);
@@ -77,11 +78,17 @@ void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     dprintf("DirectInput: Starting force feedback (may take a sec)\n");
 
+    // Auto-centering effect
     axis = DIJOFS_X;
     direction = 0;
 
-    memset(&cf, 0, sizeof(cf));
-    cf.lMagnitude = 0;
+    memset(&cond, 0, sizeof(cond));
+    cond.lOffset = 0;
+    cond.lPositiveCoefficient = strength;
+    cond.lNegativeCoefficient = strength;
+    cond.dwPositiveSaturation = strength; // For FG920?
+    cond.dwNegativeSaturation = strength; // For FG920?
+    cond.lDeadBand = 0;
 
     memset(&fx, 0, sizeof(fx));
     fx.dwSize = sizeof(fx);
@@ -93,20 +100,19 @@ void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
     fx.cAxes = 1;
     fx.rgdwAxes = &axis;
     fx.rglDirection = &direction;
-    fx.cbTypeSpecificParams = sizeof(cf);
-    fx.lpvTypeSpecificParams = &cf;
+    fx.cbTypeSpecificParams = sizeof(cond);
+    fx.lpvTypeSpecificParams = &cond;
 
     hr = IDirectInputDevice8_CreateEffect(
             dev,
-            &GUID_ConstantForce,
+            &GUID_Spring,
             &fx,
             &obj,
             NULL);
 
     if (FAILED(hr)) {
-        dprintf("DirectInput: DirectInput force feedback unavailable: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback unavailable: %08x\n",
                 (int) hr);
-
         return;
     }
 
@@ -114,15 +120,15 @@ void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out)
 
     if (FAILED(hr)) {
         IDirectInputEffect_Release(obj);
-        dprintf("DirectInput: DirectInput force feedback start failed: %08x\n",
+        dprintf("DirectInput: Centering spring force feedback start failed: %08x\n",
                 (int) hr);
-
         return;
     }
 
     *out = obj;
 
-    dprintf("DirectInput: Force feedback initialized and set to zero\n");
+    dprintf("DirectInput: Centering spring effects initialized with strength %d%%\n", 
+            strength / 100);
 }
 
 HRESULT swdc_di_dev_poll(
diff --git a/swdcio/di-dev.h b/swdcio/di-dev.h
index 82ceef0..06ac036 100644
--- a/swdcio/di-dev.h
+++ b/swdcio/di-dev.h
@@ -11,7 +11,7 @@ union swdc_di_state {
 };
 
 HRESULT swdc_di_dev_start(IDirectInputDevice8W *dev, HWND wnd);
-void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out);
+void swdc_di_dev_start_fx(IDirectInputDevice8W *dev, IDirectInputEffect **out, uint16_t strength);
 HRESULT swdc_di_dev_poll(
         IDirectInputDevice8W *dev,
         HWND wnd,
diff --git a/swdcio/di.c b/swdcio/di.c
index 35c6463..09f25d0 100644
--- a/swdcio/di.c
+++ b/swdcio/di.c
@@ -70,6 +70,7 @@ static uint8_t swdc_di_wheel_yellow;
 static bool swdc_di_use_pedals;
 static bool swdc_di_reverse_brake_axis;
 static bool swdc_di_reverse_accel_axis;
+static uint16_t swdc_di_center_spring_strength;
 
 HRESULT swdc_di_init(
         const struct swdc_di_config *cfg,
@@ -168,7 +169,9 @@ HRESULT swdc_di_init(
         return hr;
     }
 
-    swdc_di_dev_start_fx(swdc_di_dev, &swdc_di_fx);
+    // Convert the strength from 0-100 to 0-10000 for DirectInput
+    swdc_di_dev_start_fx(swdc_di_dev, &swdc_di_fx,
+                         swdc_di_center_spring_strength * 100);
 
     if (cfg->pedals_name[0] != L'\0') {
         hr = IDirectInput8_EnumDevices(
@@ -320,6 +323,16 @@ static HRESULT swdc_di_config_apply(const struct swdc_di_config *cfg)
     swdc_di_reverse_brake_axis = cfg->reverse_brake_axis;
     swdc_di_reverse_accel_axis = cfg->reverse_accel_axis;
 
+    // FFB configuration
+
+    if (cfg->center_spring_strength < 0 || cfg->center_spring_strength > 100) {
+        dprintf("Wheel: Invalid center spring strength: %i\n", cfg->center_spring_strength);
+
+        return E_INVALIDARG;
+    }
+
+    swdc_di_center_spring_strength = cfg->center_spring_strength;
+
     return S_OK;
 }