diff --git a/RefRed/calculations/lr_data.py b/RefRed/calculations/lr_data.py
index d1a9f271..6da75071 100644
--- a/RefRed/calculations/lr_data.py
+++ b/RefRed/calculations/lr_data.py
@@ -127,26 +127,29 @@ def __init__(
         # chopper settings
         use_emission_delay = False
         if "BL4B:Chop:Skf2:ChopperModerator" in mt_run:
+            base_path = mt_run.getProperty("BL4B:Det:TH:DlyDet:BasePath").value[0]
             moderator_calc = mt_run.getProperty("BL4B:Chop:Skf2:ChopperModerator").value[0]
             t_mult = mt_run.getProperty("BL4B:Chop:Skf2:ChopperMultiplier").value[0]
             t_off = mt_run.getProperty("BL4B:Chop:Skf2:ChopperOffset").value[0]
             use_emission_delay = moderator_calc == 1
 
-        wl_half_width = 1.7 * 60 / self.frequency
+        wl_half_width = 1.6 * 60 / self.frequency
         wl_delta_full_range = 0.8 * 60 / self.frequency
 
         # Calculate the TOF range to select
         if use_emission_delay:
-            # We cut 5% on each side compared to the case without correction to avoid the shoulders
-            tmin = (self.dMD * (self.lambda_requested - wl_half_width * 0.95) / H_OVER_M_NEUTRON * 1e-4 + t_off) / (
-                1 - t_mult / 1000
-            )
-            tmax = (self.dMD * (self.lambda_requested + wl_half_width * 0.95) / H_OVER_M_NEUTRON * 1e-4 + t_off) / (
-                1 - t_mult / 1000
-            )
-        else:
-            tmin = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested - wl_half_width) * 1e-4
-            tmax = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested + wl_half_width) * 1e-4
+            self.dMD = base_path
+
+        tmin = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested - wl_half_width) * 1e-4
+        tmax = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested + wl_half_width) * 1e-4
+
+        if use_emission_delay:
+            wl_min = self.lambda_requested - wl_half_width
+            wl_max = self.lambda_requested + wl_half_width
+            # Empirical additional delay to get rid of the ramp
+            ramp_delay = -750 + 125.0 * (self.lambda_requested - 4)
+            tmin += t_off + t_mult * wl_min + ramp_delay
+            tmax += t_off + t_mult * wl_max
 
         if lconfig is not None:
             autotmin = float(lconfig.tof_range[0])
diff --git a/RefRed/sf_calculator/lr_data.py b/RefRed/sf_calculator/lr_data.py
index 9296bc8a..87144763 100644
--- a/RefRed/sf_calculator/lr_data.py
+++ b/RefRed/sf_calculator/lr_data.py
@@ -76,25 +76,28 @@ def __init__(self, workspace, read_options):
         # chopper settings
         use_emission_delay = False
         if "BL4B:Chop:Skf2:ChopperModerator" in mt_run:
+            base_path = mt_run.getProperty("BL4B:Det:TH:DlyDet:BasePath").value[0]
             moderator_calc = mt_run.getProperty("BL4B:Chop:Skf2:ChopperModerator").value[0]
             t_mult = mt_run.getProperty("BL4B:Chop:Skf2:ChopperMultiplier").value[0]
             t_off = mt_run.getProperty("BL4B:Chop:Skf2:ChopperOffset").value[0]
             use_emission_delay = moderator_calc == 1
 
-        wl_half_width = 1.7 * 60 / self.frequency
+        wl_half_width = 1.6 * 60 / self.frequency
 
         # Calculate the TOF range to select
         if use_emission_delay:
-            # We cut 5% on each side compared to the case without correction to avoid the shoulders
-            tmin = (self.dMD * (self.lambda_requested - wl_half_width * 0.95) / H_OVER_M_NEUTRON * 1e-4 + t_off) / (
-                1 - t_mult / 1000
-            )
-            tmax = (self.dMD * (self.lambda_requested + wl_half_width * 0.95) / H_OVER_M_NEUTRON * 1e-4 + t_off) / (
-                1 - t_mult / 1000
-            )
-        else:
-            tmax = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested + wl_half_width) * 1e-4
-            tmin = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested - wl_half_width) * 1e-4
+            self.dMD = base_path
+
+        tmax = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested + wl_half_width) * 1e-4
+        tmin = self.dMD / H_OVER_M_NEUTRON * (self.lambda_requested - wl_half_width) * 1e-4
+
+        if use_emission_delay:
+            wl_min = self.lambda_requested - wl_half_width
+            wl_max = self.lambda_requested + wl_half_width
+            # Empirical additional delay to get rid of the ramp
+            ramp_delay = -750 + 125.0 * (self.lambda_requested - 4)
+            tmin += t_off + t_mult * wl_min + ramp_delay
+            tmax += t_off + t_mult * wl_max
 
         if self.read_options['is_auto_tof_finder'] or self.tof_range is None:
             autotmin = tmin