Tuning boxes for diesel engines work primarily by manipulating the fuel pressure signal that goes to the ECU from the fuel rail pressure sensor.
The graph below shows fuel pressure against expected engine torque and engine rpm for an example engine. Read more
Ultimately, the limit of a diesel tuning box is the factory software because,
the tuning box does not change the factory software.
We manipulate the fuel rail pressure to get the engine to inject more fuel but
as engines get more advanced, they will use more sensors to monitor the engine.
For example, Read more