As I understand it, these add-on boxes work by connecting between the fuel rail/turbo pressure sensors and the ECU. The box sends artificially reduced signals to the ECU, which causes it to increase fuel and turbo pressures to what it determines to be correct, but what, in actuality, is greater than design levels, thereby increasing BHP and torque.
My concern is that these increased pressures could eventually cause damage to seals, fuel pump, DPF and other related components.
There's also the insurance angle - if you don't declare the modification and if, say in the event of a front end collision, you were unable to open the bonnet to remove the box, you could find your claim being rejected.
I also think that, if any engine warranty claim was sufficiently substantial, BMW would probably subject the ECU to detailed diagnosis and I would think the increased pressures would be logged therein.
|