Sam, Sam, Sam... The boxes I was talking about are ANY and ALL boxes that tap onto the wires at the injection pump. The other plug-in boxes, such as the VA, PE EZ, etc. all advance the power within Cummins specs. That is, they are not asking the injection pump to do something it is not designed to do... that is what the Blue Box, and others are doing. If connect an oscilloscope (sp?) to the fuel soleniod wire when the "wire clip" boxes are working, you can see exactly what it does. They are basically adding to the duty cycle of the fuel soleniod, thereby adding fuel to each injection pulse. Pretty facinating, really. If you watch the scope on a stock or VA equipped truck, you can see there is just one spike, and that is the duty cycle of the soleniod.
I have seen boxes destroy pumps in not time, in fact, I was driving a truck when it happened. Got real quiet... The main problem with the "wire tap" boxes, is they kill your fuel pressure.
As you know, MikeR has a PowerMax3, which is a wire tap box. I said I won't ever add one to my truck, for the reasons mentioned above. The VA, PE, and others are "safer. "
BOMB SAFE, BOMB SMART.