AIRFLOW TUNING

Perfect Power Articles.

 

The airflow to an engine can be tuned in two ways:

  1. Changing the mechanical properties of the air duct, and
  2. Changing the way the ECU measures the airflow. This article is about changing the measurement.


The ECU measures the airflow, and injects the corresponding fuel into the engine. The airflow depends on the throttle position and the pressure difference over the throttle butterfly. If one likes to make the engine richer (more fuel) then one could modify the measured signal to indicate more air flow than actual, and the ECU will add more fuel.


However, a global fuel adding strategy is primitive. A ‘mapping’ strategy is called for. Mapping means to have the ability to add fuel at one particular engine operating point, and take fuel away at another point, and specify the amount according to engine temperature and other engine parameters.


Most airflow meters output an analogue signal from 0-5 volts. A few airflow meters output a frequency. Because of the different types of airflow meters it is sometimes called a Manifold Air Flow (MAF) sensor. In any case, the air temperature changes the density of the air, and thus the fuel must be adjusted accordingly. All airflow meters have an air temperature measuring circuit attached.


If it is an analogue output, then a second wire contains the air temperature. If it is a frequency airflow meter, then the temperature may be contained in the PWM (Pulse Width Modulation) or be a second wire.


The actual tuning (mapping) depends on your installation. The SMT8, SMT8L, and SMT8T can tune analogue and frequency signals. In addition to mapping the signal can be limited by setting a tuning parameter. Again, all units do this.


SUMMARY

Great feature, uncomplicated and easy to map.

 

THE FOLLOWING PERFECT POWER PRODUCTS CAN DO AIRFLOW TUNING:

SMT8 piggy-back unit
SMT8L piggy-back unit
SMT8T piggy-back unit
SMT8-FT Fuel Tuner unit
TF10 Turbo Fueller unit

 

VISIT THE FOLLOWING LINKS FOR MORE INFORMATION ON AIRFLOW TUNING:

Product Manuals
Application Notes
FAQ’s