Content Summary : Audi A8 Supercharger Calculations for the ABZ Engine The following pages are part of a mad scientist idea I had to supercharge my 97 Audi A8 with the 32 valve ABZ engine. I never executed it, I figure it would be about $6,000.00 to do it myself. I had spec’d out the Rotrex blower. I was going to increase the injector size and create a pressure ratio of 1.4-1.5 to achieve peak HP numbers of 425 to 450 HP. I was not going to change the engine management system; it is very difficult to do with the Bosch systems. Considering it is a centrifugal blower, a rising rate fuel pressure regulator would be used. It would be tuned on a chassis dynamometer using a wide band O2 sensor.