stk-code_catmod/data/nitro.xml

<?xml version="1.0"?>
<particles emitter="box">

    <spreading value="0.002"      />
    <material  file="nitro-particle.png"  />
    
    <!-- Amount of particles emitted per second -->
    <rate      min="5"
               max="10"          />
               
    <!-- Minimal and maximal lifetime of a particle, in milliseconds. -->
    <lifetime  min="1000"
               max="2000"         />
    
    <!-- Size of the particles -->
    <size      min="0.22"
               max="0.5"       />
    
    <color     min="255 255 255"
               max="255 255 255" />
    
    <!-- How much time in milliseconds before the particle is fully faded out  -->
    <fadeout   time="1500"        />

</particles>