To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
Performance with a D5 Vario:
Performance with a D5 Strong:
As can be seen the top improves on the default Laing top across the range of interest. If we compare to other tops then we see that the top performs very well and almost identically to the later revision of the top:
D5 Vario:
D5 Strong:
Summary:
A strong performing top, although you can’t buy it anymore there is no reason to upgrade if you already have one!
