Somewhat to our surprise, the cowling added another 30% or so to the thrust. I suppose it smoothed the airflow around the otherwise square valve assembly intake. We had to make sure to stop the pulsetjet before making any turn whatsoever ... it could easily tip the truck over.
But the stop stich is a sure-fire way to cut it off ... turn off the fuel pump and it quits immediately! Burns 2.2 US gallons a minute at idle and 3.3 US gallons a minuite at cruise power. Since we only have a 5 gallon tank, it wasn't going to run too long anyway.