diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index fa3f5d464b..25d204d60c 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1637,18 +1637,24 @@ void GCode::_do_export(Print& print, GCodeOutputStream &file, ThumbnailsGenerato
             this->m_objSupportsWithBrim.insert(iter->first);
     }
     if (this->m_objsWithBrim.empty() && this->m_objSupportsWithBrim.empty()) m_brim_done = true;
+
+    // SoftFever: calib
     if (print.calib_mode() == Calib_PA_DDE || print.calib_mode() == Calib_PA_Bowden) {
         std::string gcode;
-        auto s = m_config.inner_wall_speed.value;
         gcode += m_writer.set_acceleration((unsigned int)floor(m_config.outer_wall_acceleration.value + 0.5));
 
         if (m_config.default_jerk.value > 0) {
             double jerk = m_config.outer_wall_jerk.value;
             gcode += m_writer.set_jerk_xy((unsigned int)floor(jerk + 0.5));
         }
-        m_config.outer_wall_speed = print.default_region_config().outer_wall_speed;
-        m_config.inner_wall_speed = print.default_region_config().inner_wall_speed;
+
         calib_pressure_advance pa_test(this);
+        double filament_max_volumetric_speed = m_config.option<ConfigOptionFloats>("filament_max_volumetric_speed")->get_at(initial_extruder_id);
+        Flow pattern_line = Flow(pa_test.line_width(), 0.2, m_config.nozzle_diameter.get_at(0));
+        auto fast_speed = std::min(print.default_region_config().outer_wall_speed.value, filament_max_volumetric_speed / pattern_line.mm3_per_mm());
+        auto slow_speed = std::max(20.0, fast_speed / 10.0);
+        pa_test.set_speed(fast_speed, slow_speed);
+
         if(print.calib_mode() == Calib_PA_DDE)
             gcode += pa_test.generate_test();
         else
diff --git a/src/libslic3r/calib.cpp b/src/libslic3r/calib.cpp
index 0899eefb7d..e5147f428d 100644
--- a/src/libslic3r/calib.cpp
+++ b/src/libslic3r/calib.cpp
@@ -7,7 +7,7 @@
 
 namespace Slic3r {
 
-    calib_pressure_advance::calib_pressure_advance(GCode* gcodegen) :mp_gcodegen(gcodegen), m_length_short(20.0), m_length_long(40.0), m_space_y(3.5) {}
+    calib_pressure_advance::calib_pressure_advance(GCode* gcodegen) :mp_gcodegen(gcodegen), m_length_short(20.0), m_length_long(40.0), m_space_y(3.5), m_line_width(0.6) {}
 
     std::string calib_pressure_advance::generate_test(double start_pa/*= 0*/, double step_pa /*= 0.005*/, int count/*= 10*/) {
         auto bed_sizes = mp_gcodegen->config().printable_area.values;
@@ -32,11 +32,14 @@ namespace Slic3r {
     std::string calib_pressure_advance::print_pa_lines(double start_x, double start_y, double start_pa, double step_pa, int num) {
 
         auto& writer = mp_gcodegen->writer();
-        const double e_calib = 0.05; // filament_mm/extrusion_mm
-        const double e = 0.038; // filament_mm/extrusion_mm
+        Flow line_flow = Flow(m_line_width, 0.2, mp_gcodegen->config().nozzle_diameter.get_at(0));
+        Flow thin_line_flow = Flow(0.44, 0.2, mp_gcodegen->config().nozzle_diameter.get_at(0));
+        const double e_calib = line_flow.mm3_per_mm() / 2.40528; // filament_mm/extrusion_mm
+        const double e = thin_line_flow.mm3_per_mm() / 2.40528; // filament_mm/extrusion_mm
 
-        const double fast = mp_gcodegen->config().get_abs_value("outer_wall_speed") * 60.0;
-        const double slow = std::max(1200.0, fast * 0.1);
+
+        const double fast = m_fast_speed * 60.0;
+        const double slow = m_slow_speed * 60.0;
         std::stringstream gcode;
         gcode << mp_gcodegen->writer().travel_to_z(0.2);
         double y_pos = start_y;
@@ -81,9 +84,10 @@ namespace Slic3r {
         auto& writer = mp_gcodegen->writer();
         std::stringstream gcode;
         const double lw = 0.48;
+        Flow line_flow = Flow(lw, 0.2, mp_gcodegen->config().nozzle_diameter.get_at(0));
         const double len = 2;
         const double gap = lw / 2.0;
-        const double e = 0.04; // filament_mm/extrusion_mm
+        const double e = line_flow.mm3_per_mm() / 2.40528; // filament_mm/extrusion_mm
 
         //  0-------1 
         //  |       |
diff --git a/src/libslic3r/calib.hpp b/src/libslic3r/calib.hpp
index 687059a334..741891af95 100644
--- a/src/libslic3r/calib.hpp
+++ b/src/libslic3r/calib.hpp
@@ -12,6 +12,11 @@ public:
     ~calib_pressure_advance() {}
 
     std::string generate_test(double start_pa = 0, double step_pa = 0.002, int count = 50);
+    void set_speed(double fast = 100.0,double slow = 20.0) {
+        m_slow_speed = slow;
+        m_fast_speed = fast;
+    }
+    double& line_width() { return m_line_width; };
 
 private:
     std::string move_to(Vec2d pt);
@@ -22,5 +27,7 @@ private:
     GCode* mp_gcodegen;
     double m_length_short, m_length_long;
     double m_space_y;
+    double m_slow_speed, m_fast_speed;
+    double m_line_width;
 };
 } // namespace Slic3r
\ No newline at end of file