I have spoken to a number of Sling 2 and 4 owners, about the heater efficiency. They have mentioned that the amount of warm airflow entering the cabin was low. One Sling 4 owner clamps a scoop on the pickup during Winter months to increase the flow of warm air. So, I decided that my pick-up is definitely too short. I have ordered a replacement length of aluminium tubing with a ninety degree bend. I went to the hardware store and purchased a length of 40mm PVC pipe with a ninety degree bend to see if I could make a pick-up facing the air flow. The pictures show that it worked, cutting the ninety degree bend to face the airflow. Now I have a template to make an aluminium tubing pick-up, which should increase the warm air flow into the cabin.
