Most mass market automotive engines are produced with restrictive components designed to promote sound suppression, reliability and longevity. Although enthusiasts and engine tuners have successfully modified vehicles to produce more power for decades. With the relatively recent appearance of a large number of factory turbocharged motors, car manufacturers have equipped their vehicles with very conservative tuning in an effort to avoid failures. These systems offer huge reserves of untapped potential which can be safely unlocked with a simple boost upgrade. The 4-cylinder 2.0T, and 1.8T Audi TT models features a low pressure turbocharger unit (the V6 engine option is normally aspirated), which can be easily modified to improve performance.
Join the vacuum hose coming off the wastegate actuator to one end of the boost controller.
Connect the other end to the turbo outlet source line found on the compressor side.
Secure the controller with a zip-tie away from heat sources.
Turn the knob a small amount clockwise to increase manifold pressure, (boost) and perform a third gear full-throttle pass to measure psi (pounds per square inch) increase.
Repeat step 4 until desired boost level is reached. For safety use a deserted road or track to fine tune the controller.
It may take several attempts to achieve desired setting. An air-fuel gauge is recommended to monitor fuel system components and prevent a lean condition (not enough fuel in the combustion chamber compared to air mass).
Raising turbo boost beyond factory limits can potentially damage your engine. If possible have a professional Audi tuner supervise the procedure.