The Chipbox by Seletron is a simple power adder. On the 124, it connects to the Boost Absolute Pressure Sensor (Bosch 281002996, PREX1), Intake Manifold Pressure Sensor (Bosch 281006028, PREX2), and the wastegate solenoid (Pierburg valve). The box intercepts data from these sensors and manipulates it to produce more power.
I emailed Seletron asking them for more info on the box’s operation, and received this reply:
Based on this very high level explanation, I assume it just shoves more air into the engine and lets the ECU’s built in closed loop feedback do the adjustments.Fuel trim is a consequence of the manipulation of the air pressure signals Prex1 and Prex2 and pierburg valve.
By letting more air inside the combustion chamber the fuel quantity has also to increase in order to maintain an optimal fuel-air ratio (the lambda sensor will inform the ECU that it has to compensate).
Furthermore, the ignition timing is also adjusted by the ECU to prevent misfires and, again, make sure that the combustion is complete.
Amusingly the packaging proudly touts that it is made in Italy, however the Chipbox itself sports a China Export mark.
The installation instructions are a bit simplistic. More details would have been nice, but I’ve resolved that issue for y’all with the video above. Overall the installation was easy. It took around 30-45 minutes, most of which was spent getting access to the Boost pressure sensor.
The good news is it did make a measurable difference in acceleration. I captured the 40-60mph, 60-80mph, and 80-100mph times while in 4th gear. This provided nice coverage of the rev range from 2400rpm to redline. Results posted below… It averaged a a 17% increase on the top end, which if we extrapolate from the factory horsepower of 160, gives us ~187hp. Not too bad for a few hundred dollars and 30 minutes of work.