How do PD Powerboxes work?

Hey everyone,

Has anyone actually figured out how power boxes for PD motors work?
Manipulation of the control signal is prevented by the absence of ESP. Altering the fuel temperature is unlikely to produce effects worthy of being called "tuning," especially in summer when the engine is already warm.

So, how
Are they extending the injector opening time by keeping the injector's operating current on for a little longer, even after the engine computer has already started to shut it off?

Here's the translation:

'It works like this: the current signal is measured over 3-5 cycles and then passed through. In the following cycles, the current signal is shifted and extended. If the current signal is smaller than a predetermined value, such as idle, a small load, or a low fuel quantity, the signal is simply passed through.'
The problem is that the engine control unit doesn't know the actual amounts being injected. The engine is essentially running with severely reduced safety features. The diagnostics don't work correctly because something other than the pump-injector is connected to the cable, and it's essentially only controlling the amount of fuel injected, which the piston and pump-injector then have to deal with, often leading to damage. The pump housing can burst, and the piston can dissolve. Not to mention the drivetrain. The PBox claims '440 Nm and 135 kW'!! For a 110 kW pump-injector (standard) transmission, it's obviously only capable of 350 Nm plus a 10% engineering margin. Everyone should consider whether they want to subject their engine to this kind of treatment. Apart from competitive deployments.

Hello Ulf,

'In my Golf IV PD with 115 horsepower, I have a PSI tuning box installed. According to PSI, this box uses signals from the throttle position sensor and boost pressure to 'calculate' the injection time/duration.'

Only the injection duration is modified; in the case of PD boxes, the injection time is simply extended, which means that the injectors of the PD elements remain open for a longer period. It becomes dangerous with common rail systems, as is the case everywhere, when you excessively increase the injection duration. This can lead to pressure spikes of up to 2500 bar due to the shorter closing times of the common rail injectors, and it is typically at this pressure that the injectors fail.

To ensure the durability of the PD (presumably referring to a specific component or system), it should not be subjected to more than a 20% increase in power output, or a 10-15% increase in torque.