diff --git a/aichallenge/workspace/src/aichallenge_launch/launch/aichallenge.launch.xml b/aichallenge/workspace/src/aichallenge_launch/launch/aichallenge.launch.xml
index 635f8a27..0a64c95c 100644
--- a/aichallenge/workspace/src/aichallenge_launch/launch/aichallenge.launch.xml
+++ b/aichallenge/workspace/src/aichallenge_launch/launch/aichallenge.launch.xml
@@ -81,6 +81,7 @@
       <arg name="proc_stddev_vx_c" value="10.0"/>
       <arg name="proc_stddev_wz_c" value="5.0"/>
       <arg name="pose_additional_delay" value="0.5"/>
+      <arg name="extend_state_step" value="100"/>
     </include>
 
     <!-- twist2accel -->
@@ -204,12 +205,12 @@
   </group>
 
   <node pkg="simple_pure_pursuit" exec="simple_pure_pursuit" name="simple_pure_pursuit_node" output="screen">
-    <param name="use_external_target_vel" value="false"/>
-    <param name="external_target_vel" value="8.0"/>
+    <param name="use_external_target_vel" value="true"/>
+    <param name="external_target_vel" value="2.77778"/>
     <param name="lookahead_gain" value="0.5"/>
-    <param name="lookahead_min_distance" value="3.0"/>
+    <param name="lookahead_min_distance" value="3.5"/>
     <param name="speed_proportional_gain" value="1.0"/>
-    <param name="steering_tire_angle_gain" value="1.639"/>
+    <param name="steering_tire_angle_gain" value="1.72"/>
 
     <remap from="input/kinematics" to="/localization/kinematic_state"/>
     <remap from="input/trajectory" to="/planning/scenario_planning/trajectory"/>