We have tuned several E30 325i BMWs with MAF Kits and the PSC1-004 air/fuel calibrator. The kit makes a significant improvement in torque and horsepower. The dyno chart below shows a peak gain of 7 hp and 8 ft-lbs. The kit also provides a way to re-calibrate the fuel curve after various engine modifications are made.
These pictures show the detail of how the MAF 2.75 sensor is installed on the stock air box. The kit can be specified with the MAF 2.75 sensor shown or with the MAF 3.0 which has a 3.5 inch round inlet.
The following photos show the before and after comparison of the stock air flow meter and the MAF sensor.
The original rubber elbow from the air flow meter to the throttle body was replaced with BMW part number 13-71-1-726-205 which has an ideal location to install the IAT1 intake air temp sensor.