What is a MAP Sensor?
MAP stands for Manifold Absolute Pressure. This MAP sensor measures the amount of air in the intake manifold to determine the volume of air going into the engine. The ECU then uses this measurement of air to regulate the amount of fuel to inject into the engine and adjust ignition timing which we can safely say is very important for your engine to work properly.
Why would I upgrade my MAP sensor from stock?
When adding large turbos and increasing the amount of air flowing through the engine, there is going to be more pressure inside the intake manifold than the stock sensor is calibrated for. Each sensor is designed with a range of pressures in mind as well as the sensitivity to changes in pressure it can measure. When the range is exceeded (or maxed out) the MAP sensor will need to be upgraded to one that is designed for the new range. The other reason the sensor may change is due to sensitivity like when Speed Density tuning is utilized. The stock MAP sensor is calibrated to handle 2.5 BAR while an upgraded sensor may be anywhere from 3 to 4 BAR. BAR is a unit of measure for the barometric pressure. 1 BAR equals roughly 14.7 PSI (pounds per square inch).
How do I upgrade my MAP sensor?
When a higher rated sensor is installed it may have a different plug than the stock sensor did. That's why we've created our plug and play MAP adapters (see below). Just mount the new sensor with an off the shelf bracket from a company like IAG, plug in our adapter to the stock MAP plug, and then plug in the other end into your new MAP sensor. Once everything is installed we recommend tuning the car to make sure the new sensor is calibrated properly.
iWire Plug and Play MAP Adapters
MAP Adapter Version 1 - Metal Manifolds
2004-2008 Forester XT
MAP Adapter Version 2 - Plastic Manifolds
2009-2013 Forester XT
2005-2012 Legacy GT