Tech Artciles

  • OCTANE RACING

    The octane rating is a measure of the autoignition resistance of gasoline (petrol) and other fuels used in spark-ignition internal combustion engines.

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  • HEADERS

    This article should give you a basic understanding of how a header works, what the terminology means, and how it plays a part in the header's performance gains.

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  • MAFLESS TUNING

    The MAF is a component in a vehicle's intake system through which air flows past a wire that is heated by an electrical current. The airflow cools the wire, enabling the MAF to calculate the volume of airflow into the engine.

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  • COMMON ACRONYMS

    This article should give you a basic understanding of how a header works, what the terminology means, and how it plays a part in the header's performance gains.

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  • CHIPPING

    Chipping refers to replacing or modifying an EPROM chip in the vehicle's electronic control unit (ECU) to achieve better performance, whether it be more power, cleaner emissions or better fuel economy.

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MAFLESS TUNING

The MAF is a component in a vehicle's intake system through which air flows past a wire that is heated by an electrical current.  The airflow cools the wire, enabling the MAF to calculate the volume of airflow into the engine. The vehicle's engine management computer then uses this information to calculate the correct amount of fuel to be delivered to the cylinders by the fuel injection system.

When tuning a MAF-equipped vehicle to operate in MAFless mode, the MAF is removed. This requires the use of an alternative method of calculating airflow into the engine. On vehicles so equipped, such as the Holden LS1, this alternative involves the use of a manifold absolute pressure, or MAP, sensor. The MAP sensor measures pressure in the engine's inlet manifold.  When coupled with data regarding the engine's revolutions per minute, or RPM, and throttle position, the MAP sensor can be used by the engine management computer to calculate fuel requirements.

By changing the engine from MAF mode to MAFless/MAP mode, vehicle modifiers claim two advantages:

  • The MAF may pose a physical restriction across the vehicle's intake tract, thereby reducing airflow into the engine. By removing the MAF this restriction is eliminated, potentially improving engine performance. 
  • By moving the airflow measurement sensor from the intake plumbing to a point closer to the cylinders, the time lag from air moving past the sensor to reaching the cylinder can be reduced, thereby improving throttle response.

A potential disadvantage of converting an engine from MAF to MAFless mode is that where the MAP sensor is used to measure airflow, the corresponding fuel calculations must be performed by the computer based on tables of information programmed by the engine tuner. If other parts of the engine are subsequently modified with an effect on airflow through the engine, these fuel tables must be adjusted to match the revised engine hardware. By contrast, when operating in MAF mode the computer can automatically adjust its fuel delivery based on the airflow data generated by the MAF, even if other engine hardware is changed.