I was told it affects timing and with the tune I have I don't think it is wise. When I get further down the road with this deal and can ask the right people a few questions I might consider it.
Any timing effects are going to be so minimal, as to be almost not worth talking about. *almost*
The IDM mod on early trucks is much more noticeable, than on the later trucks. Even Ford/International saw the benefits of higher injector voltage.
They started at 100v, then 110v, and finally 120v. We are modifying them up to around 130-140v depending on which model of IDM you start with.
Unlike programming, you are actually making a PHYSICAL change to how the injector fires. The injectors take about ONE ELECTICAL HORSEPOWER to fire. Thats around 700+ watts of power.
At lower voltages, the amperage across the wires goes up, heat can be generated, power lost, the injectors dont "turn on" the way they should, and the end result is poor injection event.
If you also want to know why we preach having good batteries at startup, its because your IDM is drawing over 60 amps of power, you glow plugs are drawing upwards of several hundred amps, and so is your starter motor.
These computer controlled trucks are POWER HUNGRY.