My homemade power-box

In the pic below you can see my hm-powerbox.

The electric-circuit I've used is displayed below.

The timer circuit will prevent the ECU to register a fault code for fuel injection.

After 5 seconds the relays will activate the switches K1.1 and K1.2.

So both modifications will be activated at the same time.


In the upper right corner the turbo pressure booster is shown.

This diode will fool the ECU in barometric pressure.

The diode has to be placed on pin 4 of the MAP sensor.

It changes the barometric pressure from 998mbar to 785mbar . A difference of 213mbar.

The ECU will regulate the turbo to the needed pressure, butt the pressure will be 213mbar higher.

This will allow you to put more fuel in the engine by lowering the resistance of the power-box without extra fumagine.


The fuel insert duration is displayed on the right bottom side.

This circuit has to be placed between pin 2 and 3 of the fuel injector pump.

The pump plug will be a 8- or a 10-pin plug. This depended on the used motor type. My AHU needed a 8-pin plug.

The total resistance I measured between point A and B is 160 ohm.

On the pic below is shown how the electric-circuit has to be placed on the pump plug..


If you only want to use the turbo booster because you placed bigger nozzles, you can use the circuit below.

The print layout is shown below

The pic below shows you the MAP sensor on the air intake tube.



Pin 4 of the sensor is cut in two and redirected to the powerbox.



Here you can see the place of the pump plugs.


The setup of my car has been measured on a professional bench. The resistance of the power-box was the 170 ohm.

The measured values are 115 Pk @ 265 Nm!!


The resistance of the box is now 160 ohm.

Now the values are

 120 Pk @ 280 Nm !!










All risks are for your own account. If you don't know what your doing, don't even start!