This is directly from Hartge
The Hartge Engine Conversion is significantly different to other, often cheaper systems.
Our Hi-Tech system contains many "smart" technical features,
and is the result of many months of design, testing
and durability trials.
The investment we have made during the development program has resulted in a full 3 year warranty
on the hardware and software, plus an insurance backed engine and drive line warranty,
covering any effect of the increased power output for a period of 12 months
from installation date, but limited to 6,000 Euro.
Technical features are as follows:
The Hartge ECU is an external additional control unit. It is internally sealed and cannot be detected by BMW service
It is also not possible that BMW software updates can disturb the performance of the Hartge ECU. Unlike engine
management "chipping" and "flash" upgrades, it never gets overwritten during service enhancements by BMW.
The Hartge ECU is connected via a special wiring harness to the rail pressure sensor, control valve turbo charger,
boost pressure sensor 1, boost pressure sensor 2, air flow meter, water temperature sensor,
camshaft sensor (all plug and play) and power supplies.
Additional power is generated by increasing the turbo boost preassure by a precisely calculated number.
This number depending on engine speed, calcualteed engine load and other parameters.
The BMW ECU continues to monitor all other important engine parameters as standard.
Therefore the engine behaves as standard to ensure that the standard emissions controls remain intact for the standard
emissions tests and drive cycle testing.
There is also overload protection, which prevents full power from being delivered for excessively long periods of time,
for example when towing heavy loads, or driving for too long at
V-max. The Hartge ECU also prevents overload of the transmission at lower than 1,200 rpm,
and overstressing the engine at high power outputs.
In extreme temperature conditions, the Hartge ECU also monitors the exhaust gas temperature,
and if this exceeds the safe limit, the Hartge ECU reduces power accordingly back to standard BMW power.
All standard BMW engine protection and emissions systems remain in place and continue to function.
Installation at our place also includes a test drive including taking performance figures of your car
before and after the Hartge engine upgrade from 50 - 125 miles.
Also we will program your own bespoke engine mapping for your car while driving to get the best
result for your engine.
We will need your car for approx. 5 hours
BTW: I live Germany about 1.5 hrs from their installation facility