This is from Rainman in the GT forums but I think it will apply to both PT's GT and N/A.
Does anyone know about these aeroturbine (
http://www.aero-turbine.com/index.html)exhausts? They promise quite a bit:
Increased Fuel Economy
Reduced Temperature
Increased Horsepower
Increased Torque
Increased Engine Longevity
Reduced Backpressure
Does anyone have one? It seems to me like a good deal at only $199