Originally Posted by BMW DIET
what does this chip do exactly ? does it only give extra BHP ?
The chip basically increases the turbo boost and changes the computer management system resulting in higher horsepower and torque figures increasing the performance of the engine, I blew 3 e39 M5's away with the chip one my own and two others which you can see here
and the other one here
Here is more details about this incredible little widget
The Turbo Tuner is a plug-and-play solution that significantly enhances performance. Typical gains are 40 horsepower and 50 ft-lbs of torque. It is designed to be an easy-to-use solution that end users can install themselves.
The Turbo Tuner can be installed or uninstalled in seconds. It does not cause any trouble codes and its operation does not leave any trace that it was ever there. The Turbo Tuner is not an ECU re-flash solution. It is an embedded control solution that works seamlessly with the stock ECU. The turbo tuner provides real performance gains while it preserves the smooth and refined character of the car.
The Turbo Tuner is built using surface mount technology and state-of-the-art, pick-and-place automated assembly equipment for the ultimate in quality assurance and reliability. The design features a soft limit circuit that avoids overboost. This protects the engine from boost spikes and preserves drivability. There is also a temperature compensation protection circuit that lowers boost at elevated under-hood temperatures.