Performance Logging With Scanner

Would you like to know how your car is performing? Did you just install a new intake or exhaust and would like to see how much power it added? Get great performance logging easily and estimate brake horsepower from MAF sensor readings.

Take the sensor readings in the picture as an example. This is a 2007 Volkswagen GTI that is stock except for an intake. The MAF g/s (grams per second) reading is 164.05. To get brake horsepower (horsepower at the output shaft of the engine), you multiply this number by 1.25. For every gram of fuel, the engine will use approximately 1.25 grams of air. Air x Fuel = BHP. This example gives us 205hp at the crank which sounds about right for a 2.0T MKV GTI with an FSI motor. You can then estimate your driveline loss depending on 2wd or 4wd and get an approximate whp (wheel horsepower).

This number is not always perfect, especially on “chipped” cars, or cars that have larger MAFs without retuning software, but it’s a great cheap way of finding out if your bolt on part made a difference. This data and more is also invaluable to diagnosing strange performance issues with cars, even if the car is not throwing a check engine light.